Exploring the Limits of the AR Pistol

**Canonshooter** · 03-19-17, 09:21

As a 60-something guy who began shooting competitively over 30 years ago, I have always had an interest in the AR platform. I purchased my fist AR in the early 90s and though it seems I’ve been through countless iterations of it, I have continuously owned a single AR since that time. A 16” mid-length – nicely configured for my needs/limitations/expectations - currently serves as my “universal carbine.”

After decades of only owning one AR at any given time I decided to add a second with the qualities I appreciate most: light weight, compactness and useful precision - all in a KISS format. With those qualities in mind I gathered the primary assemblies for a 5.56 AR pistol to serve as a PDW platform and a possible candidate for SBR conversion: a BCM complete pistol lower and a BCM 11.5” EWL KMR-A upper. To these I have added a set of DD fixed iron sights, a MVB Micro Pistol Kit buffer assembly, a Precision Armament EFAB muzzle device and a Magpul MS4 (gen 2) sling being used in 2-point configuration.

Though there is an abundance of information on the effective use and application of the AR carbine – and plenty of training dedicated to it – there appears to be comparatively little on the AR pistol. Plenty of discussions can be found online about “pistol builds” but little on how to effectively configure and deploy one for more serious use.

Along with compact dimensions and light weight, my goal is to assemble something that is effective out to 200 yards with at least 4 MOA precision. Additionally, I want to develop the skills and technique to leverage that level of mechanical precision from field positions that a PDW might be used with.

Initial range testing – about 200 rounds indoors and out – has proven the “build” to be reliable thus far with no failures of any kind. No accuracy testing has been conducted as of yet, but on a cold blustery day here in NH (-2 degrees F., -18 F. wind chill factor) I was able to keep rounds within about six inches at fifty yards firing off hand using the two-point sling. Keeping the target stand from blowing over and seeing with my watery eyes were the biggest challenges of the day. Even with the pistol cold enough to be painful to touch with ungloved hands, it continued to tick like a clock so I am hopeful of its long term reliability.

My next range session will be in a few weeks under (hopefully) more reasonable conditions. I plan on installing a Giessele SSA before that time and spending some time on the bench getting the sights dialed-in. As with my carbine, my go-to load is the Speer Gold Dot 75 which is promoted for use in SBR barrel lengths. This load shoots amazingly well out of my carbine, often clustering shots well under 1 MOA. Once I am confident of the pistol’s mechanical capabilities, I will focus on my shooting skills with it.

I am hopeful that those here with first-hand experience on the configuration and use of AR pistols will chime in with their thoughts – I know MC4 is the place to get that. Hopefully my documentation of my own experience will contribute in some meaningful way.

To be continued…

**Canonshooter** · 03-19-17, 10:14

The Internet is filled with information, the challenge is finding any that is even remotely useful (or not completely idiotic) and then sorting the good info from the bad. Based on my very limited experience thus far, I believe that with good technique an AR configured as a pistol could be as effective as a SBR in some (or many) cases. Taken for what it's worth, this video seems to support that idea;

https://www.youtube.com/watch?v=Cx7-ONRLbFU&t=149s

At this point I remain strongly convinced that proper use of a sling is vital for effective AR pistol use.

**MistWolf** · 03-19-17, 14:21

I have found that the addition of an arm brace greatly increases the utility of an AR pistol.
It delivers about 2 moa at 200 yards, depending on ammo

A suppressor makes a good thing even better. This is how I keep it at my bedside

I've been running this pistol for some years now and I'm confident in it's performance

**Canonshooter** · 03-19-17, 14:50

Originally Posted by MistWolf

I have found that the addition of an arm brace greatly increases the utility of an AR pistol.
It delivers about 2 moa at 200 yards, depending on ammo.

Is that a 10.5" barrel in 5.56?

Nice looking rig! ...and the type of performance I am hoping for with mine.

With the sling over my right shoulder, around my back and passing under my left arm to the forward attachment point, I keep the sling under my left wrist as I grip the forearm, which helps hold the muzzle steady. Holding tension on the sling, its adjusted to place the short buffer tube on my right cheek. It all locks together remarkably well and in combination with the EFAB, the muzzle hardly moves between shots.

If I can end up shooting mine as well as you do yours, I'll be quite happy!

**MistWolf** · 03-19-17, 19:50

Yes, that's a 10.5" 5.56 barrel.

Those groups were fired while resting the weapon on a rolled up jacket

**Canonshooter** · 03-26-17, 18:04

Range Session #3

Returned to the outdoor range today under a sunny sky, no wind and 34 degrees F. - much nicer! My goal was to properly zero the Daniel Defense iron sights at 50 yards and try to get a feel for the precision potential of the pistol using irons. With the sights installed on the upper as far apart as possible I have a 15-3/8" sight radius, about the same as a standard M4.

A couple of changes from the last session;

I abandoned the Blitzkrieg Chevron Sight Post and went back to the standard post. As per the discussion here I found the chevron front sight post difficult to vertically align for precision shooting.
I replaced the PNT FCG that came with the BCM lower with a Geissele G2S two-stage trigger. While the PNT trigger is quite good for "mil-spec" I have become spoiled with the Geissele SSA trigger I use in my carbine. The G2S is the economy version of the SSA and feels identical.

I set the target at 50 yards and fired multiple groups off the bench resting the pistol on the magazine. Between the better weather and much improved trigger, three different loads averaged about 1.5" groups using iron sights. Here were a few 5-shot groups that I measured;

XM193: 1-1/2"
Black Hills 77 SMK (5.56): 1-11/16"
Gold Dot 75 (.223): 1-3/16"

POI of all three loads was very close at 50 yards. I think it's safe to say that this pistol is certainly good for 3 MOA precision or better with a variety of ammo, and perhaps 2 MOA with a RDS or LPV. IMO, not too shabby for a 5.2 pound AR "pistol" that is no longer than a 16" upper alone.

As has been the case on my previous outings, the pistol functioned 100% with the empty cases ejecting straight out the port to 3 o'clock. Through a total of about 300 rounds it has not missed a beat, which comes as no surprise for a BCM product. The MVB MPK short buffer assembly continues to function without a hitch.

Now that I've got the pistol zeroed and am confident with the consistency of POA/POI with different ammo, my next session will focus on making slow, precision shots from a variety of field positions using the sling. From there, I will move the targets closer and closer, gradually increasing the cadence of fire. As an old "bullseye shooter" I like to first master slow-and-precise and speed it up from there.

Also of interest I contacted Sig Academy here in NH and asked about using the pistol in their Rifle 102 course, which they responded that it would be OK. I'm thinking I should make that happen in my continuing exploration of the limits of an AR pistol.

To be continued...

**Diamondback** · 03-26-17, 20:13

Just a rookie chiming in, but... Interesting tech data here. I have a polymer EPL on the way I'm considering building up into a PDW-pistol, so I think I'll add your build to the reference list for possible inspirations.

Canonshooter, have you ever looked at Indian Creek's BFD blast deflector? Fits around any brake less than 1" OD, and is supposed to go a long way taming blast and flash. (Full disclosure: While I have one to go around an AFAB-556, it's neither mounted nor tested on my rig.)

**MistWolf** · 03-26-17, 23:14

Swapped the H1 out for a T2 on a Scalar Works absolute co-witness mount. The clarity of the T2 is immediately apparent and the Scalar Works mount is amazing. It's light, strong, easy to remove and reinstall with no shift on zero

Ten shot group at 50 yards using PMC 55 gr FMJ

Looking through the T2

Did a little scouting today, looking for a place to hunt rabbits and camp. Went on a couple of short walks with the Wolf Pup. The configuration shoots and carries well. Can't wait to get out again when I've got more time