Sunday, June 27, 2010

LWRC M6A2 Review - Part 1: Specifications & What's In The Box

LWRC Review, M6A2 Review, AR-15 Review, 223 Review, M6 Review
The LWRC M6A2 comes in two calibers (5.56 NATO and 6.8mm SPC) and various barrel lengths.  The rifle I'm reviewing is the 5.56 NATO with a 16.1" barrel.  The specifications for this rifle along with key information taken from the LWRC website are shown below in italics.
  • Caliber: 5.56 NATO
  • Barrel Length: 16.1"
  • Weight (unloaded): 7.3lbs
  • Length (overall length): 33.3-36.5"
  • Rifling: 1/7" RH
  • Stock: VLTOR EMod
  • Pistol Grip: MagPul MIAD
  • Sights: BUIS Front and Rear
  • Magazine: MagPul 30 rd. P-Mag
  • The M6A2™ rifle is ideal for those who utilize optical sights as it employs a low-profile gas block. There is no A-frame front sight to obscure the field of view of the optical device.
  • The M6A2™ rifle also features a longer midlength free float rail system with a removable return-to-zero top. Any M4 MIL Std 1913 accessory can be mounted to the rail, and because the rail has a monolithic profile, you can bridge devices from the receiver to the rail seamlessly. The longer rail also affords more 1913 “real estate” to mount your accessories. 
  • The M6A2™ rifle can be used in various roles. With the 16.1 inch barrel, the M6A2™ rifle can be used as a Squad Dedicated Marksman Rifle. 
  • The M6A2™ rifle’s edge in capability, reliability, accuracy and long service life is the result of advanced technology materials and manufacturing processes, combined with progressive patented designs. All LWRCI™ carbine systems feature our short-stroke gas-piston operating system. The operating system is lightweight, self-regulating, and self-scraping. This system of operation does not foul the moving parts of the weapon with carbon or heat, greatly enhancing service life and reliability while decreasing both user and armorer maintenance.
  • All M6A2™ rifles feature a match grade, cold rotary hammer forged barrel with a target crown. The barrel is treated with NiCorr™ surface conversion technology that extends service life, enhances accuracy, and increases the effective range of the weapon.
  • The action of the M6A2™ rifle is coated in our proprietary nickel coating that provides a hard permanent lubrication to the moving parts.
  • The M6A2™ rifle defines itself as the most modern and incrementally evolved carbine in the world. At the same time it also presents the best value. Service life is extended to four times that of a legacy M4, accuracy is 100 percent better, and our M6 rifles are many times more reliable than the legacy gas-impingement design.
Since I borrowed the rifle for this review, you need to keep in mind that it is not new (about 4 months old), but you will see that my friend takes great care of his toys.  Also, some items may have been left out of the box by accident when I received the rifle.  I will try to point out any discrepancies.  The photo below shows the outside of the box and the next photo is what you get inside the box when you purchase the LWRC M6A2 rifle.

I need to point out that the rifle show has had the side rail covers replaced with ladder rail guards to reduce the "fat" feel of the forearm.  The following items were in the box with links to the manufacturer's product descriptions.
Honestly, I'm a little surprised that the rifle does not come with a hard case, but since they can sometimes be of limitied use after you install your optics and accessories, maybe it was a good cost savings move for LWRC.

The rifle without magazine weighed in at 7.75 pounds.  This is surprisingly more than the manufacturers specification of 7.3 pounds, but I bet they didn't include the backup sights or the rail covers which could easily be the difference.

The lengths measured matched that in LWRC's specificaitons, 33.3" with the butt stock in the colapsed position and 36.5" with it in the extended position.

So far I like what I see and I'm eager to move on with my review.  In the next part of the review, I'm going to cover the external equipment and features.  To see the other parts of the review, go to the LWRC M6A2 Review main page.

Saturday, June 26, 2010

LWRC M6A2 Review

LWRC Review, M6A2 Review, AR-15 Review, 223 Review, M6 Review, LWRCI Review
I'm always looking for the opportunity to review a good rifle and I have a friend who purchased a LWRC M6A2 in 5.56mm NATO back in February of 2010 who was gracious enough to loan me the rifle for this review.  One of the key features on this rifle is the short-stroke gas-piston system.  With this new system and a "buy now" price on of around $2000 or more, this should be an interesting review on a quality rifle.  My friend actually purchased the rifle at a gun show in the Atlanta area for about this price.  The photos below show the rifle the way my friend has accessorized it.  If you click on a photo, it will bring up a higher resolution image.  The list of accessories below are installed on the rifle.  During this review, I plan to remove all accessories and do a complete review of what you get when you purchase a LWRC M6A2.

This review is broken down into the follow parts to cover specific details, features, and range test of the rifle.  You can click on a link to take you to each part of the review.
  1. LWRC M6A2 Review - Part 1: Specifications and What's In The Box
  2. LWRC M6A2 Review - Part 2: The Rifle
  3. LWRC M6A2 Review - Part 3: Range Test
Bottom Line:
The LWRC M6A2 Rifle is a well built and quality rifle. It has been engineered with a gas-piston operating system, coatings and finishes that should allow the M6A2 to function and outlast standard M4 rifles (they say up to 4 times which is a pretty bold claim). I was a little disappointed with the fit of the upper and lower receivers and the amount of free play, but this may be specific to this particular rifle and you should check this when purchasing a rifle. In my mind, the real question becomes; is this rifle worth the ~$2000 price? When you consider that you are going to pay more for a gas-piston system, it comes with upgraded butt stock & pistol grip, and it has the potential to last longer than other rifles due to it's coatings, it may be worth the price.  Something I really like are the split rail assembly allowing the upper portion to be removed for cleaning the piston components and the implementation of the gas-piston system.  The system is simple and comes apart quickly.  Finally, my suggestion with any rifle is to do your research before you make the investment.

Guns & Ammo also has a review found here and it is worth the read.

Leupold RX-1000 TBR Rangefinder Review - Part 5: True Ballistic Range (TBR) Rifle

Leupold Review, RX-1000 Review, RX-1000 TBR Review, Range Finder Review, Leupold Rangefinder Review
In this part of the review, I'm going to look at the True Ballistics Range for the Bow mode on the Leupold RX-1000 TBR Rangefinder.  In other parts of this review, I have verified that the accuracy of the rangefinder is within ± 1 yard for distance for Line of Sight (LOS) measurements and ± 1 degree for angle measurements.  The LOS, angle, and bow ballistic group is all that is needed for the rangefinder to calculate the True Ballistic Range (TBR) for your shot.  The table below shows how Leupold defines the Bow Groups.

I decided to check this data by going out on a 3rd floor landing and shooting to different points on the ground at various ranges for each Bow Group.  My eye level was at about 36 feet.  I felt this would be a relatively realistic test if I were hunting from my climbing stand on a clean pine tree.  This data is below.

From the data above, it looks like the Bow Group must be in the equation and is adjusting the numbers starting at about -20 degrees and at about -45 degrees at these short distances, the TBR and LOS range match.  The farther distances do seem to follow the equivalent horizontal distance (LOS x Cosine (angle)).  The best thing I can say for now is that I need to get in a tree and put this data to the test.  I'm going to hold off until I start practicing again for bow season in the fall with the hopes of the temperature dropping a little.

You can see other parts of this review by going to the Leupold RX-1000 TBR Rangefinder Review Summary Page.

Leupold RX-1000 TBR Rangefinder Review - Part 4: True Ballistic Range (TBR) Rifle

Leupold Review, RX-1000 Review, RX-1000 TBR Review, Range Finder Review, Leupold Rangefinder Review
In this part of the review, I'm going to cover some of the different True Ballistic Range (TBR) Rifle features of the Leupold RX-1000 TBR Rangefinder.  These are some of the items covered.
  • True Ballistic Range - Hold
  • True Ballistic Range - MOA
  • True Ballistic Range - BAS
As I discuss these features, I will use the "AC" group which includes the .308 Winchester 168 grain bullet at 2670 ft/sec.  I selected this groups because it matches one of my rifles (FNAR).

The first thing I wanted to do was understand the basic bullet drop equation within the rangefinder.  To do this, I used the "Hold" mode so that it would display hold values.  The hold values are the inches above or below the target that I would hold and are basically bullet drop values.  I found a flat area and measured these values for every inch of hold between 200 and 500 yards.  I also included some data on out to 700 yards for approximately every 5 inches of hold.  You can see this data in the graph below (clicking on the graph will bring up a larger image).  I also plotted the ballistics data for the .308 Winchester 168gr Ballistic Silvertip (2670 ft/sec) which is shown by the red diamonds.  This data lined up very good with the Hold data from the rangefinder.  Since they also stated in the Leupold Rangefinder Owner's Manual that this group also contains the .308 Winchester 150gr (2820 ft/sec), I plotted the ballistic data for the Winchester Power-Point shown by the green diamonds.  Notice that there is a significant difference.  I have to assume that Leupold must be referring to a bullet with a different ballistic coefficient than the Power-Point due to the mismatch.  I had MS Excel create a trend line and I have shown the equation for this line on the graph.  If you are using Group AC, I recommend plotting this line and then comparing the rangefinder data against the actual ballistics for your cartridge.

The next mode I checked was the "MOA" mode.  Again, I found a flat place and checked this mode between 200 and 500 yards for every MOA value which ended up being 1 through 9.  Since the rangefinder does not show any fractions of a MOA, I also made sure I found where the yardage change was between each MOA value.  You can see this data in the graph below shown in blue.  This data looks like a stair step because a single MOA value covers a range of yards from 39 yards at 1 MOA to 25 yards at 9 MOA.  Because of this range per MOA, there will be error introduced.  The error introduced will be a function of the ballistics of your cartridge versus where the tarted actually falls within the range.  I included in the graph below the ballistic data for the .308 Winchester 168gr Ballistic Silvertip (2670 ft/sec).  Just like in the "Hold" data, you can see this appears to be a good match.  Again, I included the .308 Winchester 150gr Power-Point (2820 ft/sec) to show that you need to be careful to check your cartridge and make sure it falls within the ballistic range recommended by Leupold.

To better understand what this range means from a drop perspective, the data below shows the bullet drop range for each MOA.  For example, if the rangefinder says 4 MOA and you adjust the scope 4 MOA, the bullet drop range is 4.9".  From the graph above, the 168gr bullet falls near the mid range of the 4 MOA range.  This means that the total range is 4.9", so the variation in my bullet point of impact may be +/- 2.45".  Out at the 9 MOA range, it would be +/-3.65.
  • 1 MOA, 220-258 yards, 2.8" bullet drop
  • 2 MOA, 259-295 yards, 3.6" bullet drop
  • 3 MOA, 296-329 yards, 4.2" bullet drop
  • 4 MOA, 330-362 yards, 4.9" bullet drop
  • 5 MOA, 363-393 yards, 5.4" bullet drop
  • 6 MOA, 394-423 yards, 6.0" bullet drop
  • 7 MOA, 424-451 yards, 6.3" bullet drop
  • 8 MOA, 452-478 yards, 6.8" bullet drop
  • 9 MOA, 479-504 yards, 7.3" bullet drop
Personally, I wish Leupold would have come up with some way to show fractions of a MOA to match my 1/4" adjustment capability of my scope.  This 1 MOA increment may be OK for big game hunting, but I think it could be better.

The last rifle mode is the "BAS" mode which is to be used with Leupold's Ballistics Aiming System® reticles or gives the equivalent horizontal range.  In this mode, if there is no up or down angle for the shot, the TBR range will match the LOS (line of sight) range.  The rangefinder is taking the LOS range and the angle to the target to determine the range you should use for shooting.  Since the rangefinder measures and uses the angle in the calculation, I needed to determine the accuracy on the angle measurement.  I set the rangefinder up on a tripod and measured the horizontal (0 degree) distance to a wall and marked that location on the wall.  Next I rotated the rangefinder down in 2 degree increments from 0 to 54 degrees down and marked each location.  Last I measured the distance on the wall from the 0 degree mark to each 2 degree increment.  After doing the math on this data, it worked out that every measurement was within 1 degree, therefore I believe the angle measurements to be within +/- 1 degree.  Since mine was not an overly precise method, it may be even more accurate, but this is good enough for this type of a device.  Since I was already setup, I checked the up angle accuracy to 20 degrees and again the accuracy was the same, +/- 1 degree.

Now that I have established that the LOS accuracy is good and the angle measurement is good, I have to believe that the equivalent horizontal range (TBR in the BAS mode) will be good since this should only be a simple calculation if you use the Rifleman's Rule found at Wikipedia.  The TBR range should be the LOS times the cosine of the angle which give the horizontal range.  Since I don't live in a mountainous area, for now I'm going to take Leupold's word on this mode.  If I get any data that says this is not the case, I will update this part of the review.

You can see other parts of this review by going to the Leupold RX-1000 TBR Rangefinder Review Summary Page.

Tuesday, June 22, 2010

Leupold RX-1000 TBR Rangefinder Review - Part 6: Parts, Pros, Cons, and Bottom Line

Leupold Review, RX-1000 Review, RX-1000 TBR Review, Range Finder Review, Leupold Rangefinder Review
Since this review was very involved, I decided to break the review down into the different parts below.  You can click on these links to see the other parts.
  1. Leupold RX-1000 TBR Rangefinder Review - Part 1: What's In The Box
  2. Leupold RX-1000 TBR Rangefinder Review - Part 2: Functions, Menus, and Optics
  3. Leupold RX-1000 TBR Rangefinder Review - Part 3: Accuracy
  4. Leupold RX-1000 TBR Rangefinder Review - Part 4: True Ballistic Range (TBR) Rifle
  5. Leupold RX-1000 TBR Rangefinder Review - Part 5: True Ballistic Range (TBR) Bow
  6. Leupold RX-1000 TBR Rangefinder Review - Part 6: Parts, Pros, Cons, and Bottom Line (this page)
  • Solid compact device
  • Outstanding optics
  • Good battery life
  • Accuracy within +/- 1 yard to 100 yards and my evaluation says +/- 1.5 yards out to 500 yards
  • Easy to use functions & menus
  • I have a preference for a 123A battery over the CR2. The CR2 is actually smaller and perhaps a 123A could not have fit. This is probably more of a comment than a con.
  • I wish Leupold would have added some way to show the TBR MOA data to one decimal place so that I could use the 1/4 click adjustments on my scope instead of only having one MOA resolution on the data. 
Bottom Line:
I'm have been very pleased with the Leupold RX-1000 TBR Rangefinder and would recommend it to anyone.  It is a solid, compact, and accurate rangefinder with great optics.  The True Ballistic Range (TBR) features should prove to be worth the money when on those critical hunts.  As with all high tech gadgets, you need to spend some time understanding how your rifle or bow matches up to the TBR data so that you have the greatest chance of success.  Also, you should remain a responsible hunter and only make shots that you feel you are skilled to make.  There is a lot more to taking a 350 yard shot than just knowing the distance (i.e. rifle accuracy, shooting position, personal capability).

Saturday, June 19, 2010

Leupold RX-1000 TBR Rangefinder Review - Part 3: Accuracy

Leupold Review, RX-1000 Review, RX-1000 TBR Review, Range Finder Review, Leupold Rangefinder Review
So far I have covered the basic geometry of the Leupold RX-1000 TBR Rangefinder in Part 1 of this review.  In Part 2 I covered the rangefinder's functions and menus along with the optical quality.  In this part of the review (Part 3) I plan to cover the accuracy of the rangefinder and in Part 4 I will discuss some of this rangefinder's bullet drop compensation features.  Below in italics are some of Leupold's stated features that I covered in this review.  Throughout my review, all my measurements were made in yards.

> Min Range 10.0 yd / 9.1 m (Confirmed)
> Close Focus Distance 18.0 ft / 5.5 m (Confirmed but not for older eyes)
> Accuracy (per the Owners Manual page 7): +/- 1 yard/meter at distances less than 100 yards/meters (Confirmed)
> Angular Field of View (degrees) 6.0 (Confirmed)
> Linear Field of View (ft/1000 yd) 320 (Confirmed)
> Linear Field of View (m/1000 m) 97.5 (Seems low based on my numbers)
> Max Range (Deer) 500 yd / 457.2 m (No deer measured, but plenty of other stuff)
> Battery Life: At Least 2,000 measurements (Actual number unknown, but battery life is not an issue)

For the accuracy of the rangefinder, I compared the readings against the Leica Disto™ A3 which is accurate to +/- 10mm out to 328' (0.4 inches out to 109 yards).  For ranges less than 100 yards (really less than 50 yards which is the absolute maximum for most bow hunters), this should be more than sufficient for comparing accuracy since the Leupold RX-1000 TBR Rangefinder is only stated to be within +/- 1 yard out to 100 yards.

I started out with the rangefinder in LOS (line of sight) mode and only took the data below for distances less than 100 yards.  The first number represents the Leupold Rangefinder and the second number represents the Leica Disto™ A3.  The difference between the two rangefinders is calculated as shown below also.  Keep in mind that the resolution of the Leupold Rangefinder in this mode is to 1/2 yard and the Leica is less than an inch.  I'm not sure how Leupold rounds to the half yard but there can be anywhere between nearly 9" to 18" of error in their measurement compared to that of the Leica.  These measurements were made against my brick mailbox at about an hour before dark.

    #.  Leupold - Leica = Difference (yards)
  1. 10.0 - 10.8 = -0.8
  2. 12.0 - 12.5 = -0.5
  3. 18.0 - 18.1 = -0.1
  4. 20.0 - 20.2 = -0.2
  5. 23.5 - 24.5 = -1.0
  6. 25.5 - 26.0 = -0.5
  7. 28.5 - 28.7 = -0.2
  8. 32.5 - 32.4 = -0.9
  9. 40.0 - 40.3 = -0.3
  10. 51.0 - 51.3 = -0.3
  11. 61.0 - 61.3 = -0.3
  12. 78.5 - 78.9 = -0.3
  13. 84.0 - 84.1 = -0.1
  14. 91.5 - 91.3 = +0.2
  15. 102 - 102.0 = 0.0
I think this clearly shows that the Leupold RX-1000 TBR Rangefinder is accurate within +/- 1 yard within the 100 yard range.

As I was doing the close range measurements above, it was clear that my older eyes (yes, bifocals) can not achieve the minimum close focus distance with the focus ring adjusted to make the overlaid display also be in clear focus.  With both in clear focus it was about 60 feet (20 yards) for my bifocal eyesight, not the 18 feet listed.  If I adjusted the eyepiece and didn't care about having the display in focus, I was able to make the rangefinder focus on objects approximately 18 feet away.  I don't see this as an issue because I'm not overly worried about anything within 20 yards anyway and I can live with a little out of focus within this lesser range.

Next I checked the angular field of view of 6 degrees by measuring the distance to an object and having the object fill the entire field of view of the rangefinder.  I used a large circular plate that was 17.13" and it filled the field of view at 13' 3".  When you do the math, this comes up as 6.17 degrees.  Since there are some inaccuracies in my measurements, I believe that Leupold's advertised value of 6 degrees is correct.  Also since linear field of view is directly related to the angular field of view, I calculated the linear field of view and came up with 314" at 1000 yards.  That is close enough to Leupold's stated 320" for me to say the data is confirmed.  I was a little surprised that the linear field of view in meters value was not closer to Leupold's linear field of view value.  I came up with 105 meters at 1000 meters, where Leupold states 97.5 meters.  This is a 24' difference.  Personally I think something is hosed somewhere in Leupold's math or I don't understand the difference between how they measure feet versus meters.  In the end, none of this really matters because you are going to get what you get and I don't think you will be dissatisfied.

At this point I wanted to get a better understanding of how big the actual ranging area of the device was.  I went outside and placed a basketball on top of a boot so that the the ball was off the ground and the background of the ball was clearly at a much different distance than the ball.  As I tried to range the edge of the ball, what I found was that if the very center of the cross was not on the edge of the ball it gave me the background range.  In my mind, the Leupold rangefinder has a very precise ranging area.  I would love to find out how the actual ranging area works.

The center of the cross that forms the clear square seemed to be the ranging area.

After establishing the accuracy of the rangefinder out to ~100 yards, I decided to use it to help me determine the accuracy out to 500 yards.  To do this, I was able to range to specific wall sections of a very long building.  The distances between each wall section was less than 100 yards (about 67 yards).  It was a very convoluted method, but in the end, I was comfortable that the accuracy out to 500 yards was within 3 yards for all of my multiple measurement methods.  This ends up being +/- 1.5 yards.  Throughout this test, I was ranging on a 4' x 7' white electrical box at about 3 hours before dark.  Since Leupold does not state an accuracy of this rangefinder for greater than 100 yards, this is some good data.  As a second check I was able to see two reference points on Google Earth which were 492 yards per my measurements and also with Google Earth.

So far the longest object I have ranged was a white building at 697 yards.  For my purposes, I'm not really worried about anything out past 500 yards anyway and that is probably still a stretch.  At this point, my wife thinks I'm nuts and my neighbors probably think I'm a peeping Tom because I carry this on walks, drives, and the kids sports.  As I get more data, I will update the maximum yardage.

One thing I need to point out is that when you are ranging an object at the longer distances, you have the same issue you would have with aiming your rifle freehand.  You really need to hold still so you can get on target.  A deer out at 500 yards would be a struggle to range freehand, but not impossible.

Finally, I need to comment on battery life.  At this point I have no idea of the number of times I have ranged objects.  I'm sure it is well into the hundreds.  I have actually owned the rangefinder for about 4 months and cannot imagine battery life being an issue.  Leupold says "at least 2000 measurements".  I believe it, but a smart man would still toss a spare battery in his hunting pack and yet it will probably be a long time before it is needed.  I do wish they would have used a 123A battery instead of the CR2 battery.  I already carry spare 123A batteries for my flashlight.

You can see other parts of this review by going to the Leupold RX-1000 TBR Rangefinder Review Summary Page.

Monday, June 14, 2010

Leupold RX-1000 TBR Rangefinder Review - Part 2: Functions, Menus, and Optics

This part of the review covers the Functions and Menu features along with the optical quality of the Leupold RX-1000 TBR Rangefinder.  If you missed reading Part 1 of the review you can find it at this link Leupold RX-1000 TBR Rangefinder Review - Part 1.  Part 1 covers the geometry of the rangefinder.  The below in italics lists some of the features that Leupold states about this rangefinder and I will try to cover these features in this portion of the review.

> Bright colorful optics, markedly brighter than previous rangefinders.
> 6x magnification gives you plenty of power, with a wide field of view to track movement.
> Three user adjustable intensity settings allow you to perfectly match the OLED display to dynamic lighting conditions.
> Three selectable reticles
> Includes a built-in inclinometer.
> A newly redesigned Quick Set Menu® uses on-screen prompts for exceptionally intuitive and easy use in the field.
> Battery power indicator for easy battery level checks.
> Multiple ballistics settings…True Ballistic Range (TBR®) provides accurate aiming information matched to the performance of your rifle or bow. By calculating the incline, line of sight range to the target, and a projectile’s ballistics, your RX provides rifle hunters using Leupold Ballistics Aiming System reticles as well as bow hunters the correct equivalent horizontal distance for precise shooting on an incline. In other words, aim using the True Ballistic Range, not the line of sight range. Rifle hunters can also get this data as an MOA adjustment or a holdover point. With practice, long distance/steep angle shooting will become second nature. TBR is effective to 800 yards for most rifle cartridges.

The two buttons required to control the rangefinder are on the top (Power) and left side (Mode) as shown below.

When you first press the Power button, the rangefinder will show a display similar to this photo below.  The reason I say similar is that the rangefinder is displaying the configuration that I have already setup for my use.  In this view, I have mine setup to show the True Ballistic Range (TBR) based on the Ballistics Aiming System (bAS) distance for the TBR Group AC.  This group is for my .308 rifle. I will explain more thoroughly later in the review.  The units will be displayed in yards (YD) and the rangefinder will also display the Line of Sight (LOS) distance along with the angle from horizontal. The battery life indicator is always displayed when the unit is turned on.  Keep in mind that everything I'm going to show with regard to the Functions and Menus can be found in the Leupold's owners manual.  Hopefully my efforts will make it a little easier to read and provide further clarification.  Also, if you click on a photo, it will bring up a higher resolution photo.  It was extremely difficult to get good photos looking through the rangefinder.  If the image is not clear in some of the photos, that is my fault, not the rangefinder.

Pressing the Power button a second time will cause the rangefinder to measure the range.  In the photo below, the trees are 37 yards from my deck and because I was only at a 1 degree angle, the True Ballistics Range (TBR) and the Line of Site (LOS) range are the same.

To give you an idea of the clarity, the photo below of the tree trunk is approximately 37 yards away.  Notice the chain wrapped around the tree.  The second photo is zoomed in on that chain.  The detail you are able to see is unbelievable.  Also it is hard to appreciate, but I'm taking this photo with a Sony point-and-shoot camera while holding it up to the eyepiece of the rangefinder.

Another example of the image quality is shown below.  I am very impressed with the brightness and clarity of the optics in this rangefinder.  In this photo, the house is 133 yards away.

Function 1: True Ballistic Range
Once the power button is pressed, the unit is turned on and you can access the menus by pressing the Menu button and holding it for about 1 second.  The first Menu item is the True Ballistics Range (TBR).  Once in this mode, pressing the Power button will toggle between on or OFF.

TBR - on

Pressing the Menu button again allows you to set (SEt) the type of TBR data to display.  Pressing the Power button will toggle between the three different modes.  Out of all the sections in the owners manual, you should read this section because this is the heart of the TBR function.  The three different modes are:

  • HOLd (Hold) - Displays the appropriate hold over or under amount based on your ballistic group and sight-in distance.  When set, the upper display will flash "HI" or "LO" and then the hold amount in inches or centimeters based on the units you select.

  • MOA (Minute-of-Angle) - Displays the minute-of-angle adjustments based on your ballistic group and sight-in distance. When set, the upper display will flash "UP" or "dN" and then the MOA adjustment.

  • bAS (BAS or Ballistic Aiming System)- The upper display will show the equivalent horizontal range based on your ballistic group and sight-in distance.
SEt - bAS

Function 2: Rifle Ballistics Groups
The rangefinder has seven rifle ballistic groups.  Leupold has selected these groups generally to keep the error down to less than 2.5"  of bullet impact out to 500 yards.  The tables below show the cartridges identified for each group.  If you have a cartridge that is similar to the ballistic data of one of these, you should choose that group.

Leupold's quick reference card looks at this same basic data but in terms of bullet drop.

Once you are in the Group (GrP) mode, you can toggle to the correct bullet group for your cartridge.

Function 3: Bow Mode
The next mode is the Bow mode.  When in the Bow mode, it automatically deactivates the rifle mode and you must select a Bow Group that corresponds to your bow.  The Bow Group Data is shown above.  Press the Power button to toggle between Bow on or OFF.

BOW - on

Once the Bow mode is on, you can press the Mode button again and it brings up the Group (GrP) screen.  Pressing the Power button toggles between the three possible Bow groups.  Below you can see I have selected group C.
GrP - C

Function 4: Display Intensity
The Display mode is used to adjust the brightness of the display.  There are three different brightness levels, Lo, Md & Hi.  The power button toggles through these different display brightness levels.

dISP - Lo
dISP - Md
dISP - Hi

There is a second method for adjusting the display brightness.  Press and release the Power button to activate the rangefinder, then press and hold Power.  While Power is  held depressed, press and hold the Mode button for 1 second.  After 1 second, release Mode; each subsequent depression of Mode will cycle through the available intensity settings.
Function 5: Units
The rangefinder can display units in yards or meters.  When in the Units mode, you can toggle between yards and meters by pressing the power button.

UnIt - YD
UnIt - M

Function 6: Last (Farthest) Target Mode
This mode is to display the distance to the farthest (Last) object when the unit may be reading more than one object.  Leupold says that multiple objects will often return an average distance and this mode ensures an accurate reading to the farthest object. You can toggle between the "on" mode and "OFF" mode by pressing the Power button.


Function 7: Line Of Site Mode
This is the straight line distance (Line Of Sight) to the object and is displayed in the lower portion of the display.  You can toggle between the "on" and "OFF" mode by pressing the Power button.  If you turn off the rifle and bow mode, LOS will turn back on automatically.

LOS - on

Function 8: Reticles
You have three choices for the reticles.  My preference has been the Plus Point only.  It is very visible and covers the minimum amount of your viewing area.

 Plus Point™
Duplex® with Plus Point™
Duplex® without Plus Point™

To summarize this part of the review, I feel that this rangefinder has true optical quality.  Every time I use it, I find myself impressed with the brightness and clarity of the image.  Also I feel that the functions and menus seem manageable.  If I were to say one thing negative, it would be how they jump from upper to lower case letters and until you get the hang of this, it may be a little confusing.

This concludes Part 2 of the Leupold RX-1000 TBR Rangefinder Review.  I will be working on Part 3 of the review in the near future.  Part 3 will cover the accuracy of the rangefinder along with some dialog on the methods used for their bullet/arrow drop compensation.

Friday, June 11, 2010

Mako Recoil Reducing AR-15 Butt Stock With Cheek Piece Review

Mako Stock Review, GL-SHOCK Review, GL-SHOCKCP Review, AR-15 Buttstock Review
Over the past few months I have been adding accessories to my older Colt AR-15 Sporter II.  One of the accessories I added was a UTG 6 position retractable stock.  I decided to go with this stock mainly because it was an inexpensive route for getting a M4 buffer tube assembly.  The stock itself is very plain and I had intentions of swapping the stock eventually.  That leads me to this review.  The Mako Group (Mako from now on) has just released a new product on the market.  It is their Model GL-SHOCKCP Revolutionary Recoil-Reducing AR-15 Butt Stock And A Cheek Riser (that's a mouth full).  There are a couple of things that I was very interested in trying out, such as the recoil reducing feature and the cheek piece.  I'm 6' 2" and 215 pounds, so recoil doesn't bother me on a .223 rifle, but this stock is supposed to be a drop-in replacement on a M4 buffer tube.  This means I could possibly swap it out on a AR-10 style rifle or shotgun in the future.  The other feature I liked was the Cheek Riser.  Since my AR-15 has a carry handle, my optics are always so high that I never got a cheek weld with the standard A2 butt stock.  That is why I decided to get the Mako GL-SHOCKCP stock and do this review.  You can purchase this stock from Mako for $119.05 plus S&H.

When you get your stock, you're going to see that Mako doesn't spend a lot of money on packaging or instructions for this product.  To be fair, none is really needed. The stock is durable (which it should be) and installation is simple (details later in the review).  The next two photos show the stock in the package and then the opposite side of the top of the package.  Throughout this review, if you click on a photo, it will bring up a higher resolution image.

The next set of photos show the stock after you take it out of the bag.  My first impression was that it is a solid piece of hardware.  There are no parts that rattle and it has a good look and finish.

To access the battery compartment, you push down on the lever shown in the right photo above.  While pushing down, you then slide the removable rubber butt pad down and off the stock.

The rubber butt pad is locked in place with a tapered dovetail slot.  When locked in place, it is firm and has no rattle.  I also like the rubber tread pattern and texture of the pad.

To remove the battery compartment plug, you pull out on the dovetailed portion of the plug.  There is an o-ring around the plug which makes a very tight and waterproof fit.  I actually had to pry with the back of my knife blade to get it to start moving and then it popped out.

As a test, I decided to check the waterproofing of the battery compartment.  I ran water over the plug for about 3 minutes while angling the stock so that water was pouring directly over different sealed areas.  When I removed the plug, I couldn't find any indications of water inside the compartment.

The battery compartment is designed to take two AA or two 123A batteries.  The photo below shows that there is a small ridge about two thirds down the battery compartment that prevents the 123A batteries from dropping in further.  Also this ridge helps reduce rattle for the longer smaller diameter AA batteries.

The photo below shows a AA on the left and a 123A battery on the right.  One thing I did not like was that after you reinstall the battery compartment plug, the batteries rattled inside the compartment.  If Mako could incorporate two small springs on the bottom of the cap, this could be fixed.

I decided to solve this rattle problem by placing an ear plug on each battery and then reinstalled the cap.  This actually worked nicely.  The cap was easy to get back into place.  For some people this rattle may not be a big deal, but for me, I'm a freak when it comes to rattles.  An example is that I usually wrap tape around my batteries on flashlights to help the fit inside the flashlight tubes.

The photo below shows the cheek riser in it's full extended position.  The two molded thumb nuts on each side of the stock are used to adjust the height of the cheek riser.  The riser will adjust up about 1.16".  There are no specific adjustment increments, so it is infinitely adjustable through it's range.  I was very impressed with the fit and smoothness of the cheek riser.  With the thumb nuts loosened, it slides up easily and then after snugging the nuts, the riser is held firm in place.  The thumb nuts house regular metallic nuts which have a locking feature (nylon I think) so that even when the nuts are loose, they will not rattle off. 

If for some reason you decided you did not want the cheek riser and also wanted to drop some weight out of your rifle, the riser can be easily removed.  The weight of the riser and mounting bracket is 2.78 ounces.

The weight of the GL-SHOCKCP without the cheek riser installed was 10.58 ounces.  This is slightly heavier than the stock it is replacing which weighed in at 7.55 ounces.  Considering the fit, battery compartment, butt pad, and the capability to install a cheek riser, I think it is worth the weight.

To install the stock, you grab the back sides of the lever and pull down until the locking pin is flush in the slot as shown below.  Then you can slide the stock over the buffer tube.  Also notice that the pin is all the way forward in the slot.  This slot allows the pin to be up and locked in the buffer tube and then allows the tube to move back when the internal spring inside the stock is compressed due to the recoil of your rifle.

Since this stock is a drop-in replacement that will fit both mil-spec and commercial buffer tubes, all I needed to do was remove my old stock and slide this one on my commercial buffer tube.  This is where I ran into an issue.  It seems that my commercial buffer tube was on the high side of the tolerance band and this was causing a tube/stock fit that was clearly too tight.

For those of you who are not familiar with the differences between a mil-spec and commercial buffer tube, a mil-spec buffer tube outside diameter should be between 1.145" to 1.150" and a commercial buffer tube outside diameter should be between 1.163" and 1.173".  You can see a good comparison of these two by checking out this link and viewing a comparison diagram.  The GL-SHOCK stock is designed to fit both, with the tighter fit being on a commercial tube.

I contacted Mako and was able to provide my information to their engineering department.  Mako engineering then did a thorough investigation and decided to tweak their mold to allow a better fit for commercial buffer tubes which seem to be coming in on the high side of the tolerance band.  Their investigation also revealed that most of these types of tubes were imported and that they had not run across this issue on any US made commercial buffer tubes.  If for some reason your commercial buffer tube and GL-SHOCK is too tight similar to my situation, you should contact Mako and they should be able to swap your product with an updated version.  Mako is sending me a new stock so that I can evaluate the fit against my larger buffer tube and also to evaluate the recoil reducing feature.  I will discuss both of these further in this review.

With my original stock now installed on my rifle, I decided to compare the different positions of the stock with reference to my old A2 stock.  The length shown for each position is shown from the edge of the lower receiver to the back top of the butt pad.

Position 1 - Length 7.75"

Position 2 - Length 8.50"

Position 3 - Length 9.25"

Position 4 - Length 10.12"

Position 5 - Length 10.88"

Position 6 - Length 11.45"

If you plan to use the stock in Positions 1, 2 or 3, you will get binding of the charging handle if the cheek riser is all the way down.  You can see this binding below with the stock in Position 1.

The first position that the charging handle does not lap over the cheek riser is Position 4 shown below.

If you are using the cheek riser, you may not have any issue with the charging handle if the riser is high enough for the handle to go under.

To evaluate the cheek riser height, I installed an older scope that I had sitting around my gun room.  Believe me, this is not my final optics choice for this rifle, but it has been a good scope for over 30 years.  I found the cheek riser a welcomed addition.  Over the years I have had other scopes on this rifle and have removed them because I didn't like the feel of not having my cheek on the butt of the the rifle.  I can already see that I'm going to start looking for a worthy scope for this rifle.

Up until now, I have done the review with my original stock which had the tight fit.  As you may have noticed in some of the photos, there are wear marks that are being formed on my buffer tube.  Also, I applied graphite and then finally a spray silicon to reduce the friction when moving the stock into it's different positions.  The combination of surface finish wear and lubricant has greatly helped reduce the tightness of the stock. Over time they may break in like a baseball glove and produce a great fit.

After a couple of weeks, Mako sent me a new stock based on their modified mold to allow more clearance for commercial buffer tubes.  I'm very impressed with how fast Mako jumped on this issue and were able to provide a newly manufactured configuration.  There is no visible difference between the stocks, but there is clearly an increase in size of the buffer tube area to allow a much better fit for the commercial tubes.  The new stock drops on a mil-spec tube and functions nearly like any other stock when changing positions.  What I mean by nearly is that it actually functions better because Mako has integrated spring acting tabs that will press against the buffer tube to reduce any free play (rattle) which may exist.  You can see these tabs on both sides of the locking pin in the photo below.

When I put the stock on my commercial buffer tube, it still has a snug fit for my tube, but this is my preference.  It is not so tight that making adjustments takes an act of congress, but it is snug.  This will vary per buffer tube because there can be tolerance differences.  I measured my tube and it is on the high side of the tolerance band.

The next feature to evaluate is the recoil reducing feature.  Just to be clear, when I talk about this recoil reducing feature, it is in terms of "felt recoil".  Felt recoil is your perception of the recoil.  The addition of springs helps spread the recoil over a longer period of time which gives the rifle a softer feel and thus less felt recoil.  For more information on recoil, you can read this article from Wikipedia.

To evaluate the recoil reducing feature, I installed the new updated stock from Mako. I did have some doubts on it's effectiveness with my standard 55 grain (1293 ft.lbs. @ muzzle) plinking ammo and felt like I would need to shoot some heavier bullets to really feel the difference.  I ended up getting a couple of boxes of BVAC 75gr HPBT Match ammo.  This ammo has a muzzle energy of 1261 ft.lbs.  On paper, these two cartridges seem nearly identical when you compare the muzzle energy, but I know that the heavier bullet will give a slightly increase recoil based on my experience.

The big issue I had was how to really measure the reduction in recoil without it becoming just my opinion.  Since the stock recoil reducing feature is based on spring compression, I decided to try and see how much spring compression I was actually getting when I shot my rifle.  The final (cheap) way I decided to measure the spring compression was to set up some markers at different increments along the travel of the locking pin.  I setup a series of strings along the path of the locking pin.  The strings were attached by tape to the stock.

The first photo below shows the stock in the initial position (before compressing the spring).  The second photo shows what happens to the string around the pin when I compress the stock to the first horizontal string above the locking pin.  The third photo shows what happens to the strings when I press the stock to the second horizontal string.

After shooting the 55 grain .223 ammo, I could not see any change in the string around the locking pin, which tells me that the recoil reducing spring was not compressed due to the recoil of this ammo.

Next I switched to the 75 grain .223 ammo.  The photos below show the before and after condition of the strings when shooting the 75 grain ammo.  You can clearly see that the string in the after photo is no longer tight around the locking pin.  This means that there was a slight spring compression, but you can also see that the spring compression was not as far as the first horizontal string when you compare to the photos above.

Before                                                            After

Since I don't own a fully auto rifle (yet), I'm limited to making shots at the rate of me actually pulling the trigger.  I tested this with a couple of three round quick shots and achieved the same results.  What does all this mean for the recoil reducing feature? The bad side is that I don't think this feature will make any significant difference on a standard (not auto) .223 rifle.  The good side is that anything with more recoil than a .223 will see a real reduction in recoil (compression of the spring).  If I had a buffer tube on one of my shotguns, I would drop this in and check it out, but at this time I don't.  Based on my results, I have no doubt that this would reduce felt recoil on any larger caliber.

Bottom Line:
I would consider this stock to be in the higher end category.  When you consider the fact that it has waterproof storage and a cheek riser, and then compare the price to others on the market, I believe this stock provides a good value.  Since it is already a good value without the recoil reducing feature, I consider this feature to be a bonus.  Just because the recoil reducing feature is not very effective on a standard (not auto) .223 rifle doesn't mean it can't be swapped out in 30 seconds to a .308 rifle (AR-10 style) or shotgun which will have more recoil.