AR-15 Pistol Build: Components & Considerations

posted on October 14, 2018

We’ve built a rifle. We’ve built a carbine. We’ve even built a super-lightweight carbine. Now, it stands to reason, we need to build an AR-15-based pistol. Since we’re seeing a relaxation of the near-decade-long rush on parts, now is an excellent time to put together a top-tier AR-based firearm at a reasonable price, and AR pistols, while not as hot as they were a few years ago, are still in high demand.

Pistols chambered in 5.56 NATO are certainly not new; we’ve profiled the Bushmaster Arm Pistol in our “Classics” column, and the sidearm dates to the early 1970s. AR-15-style pistols have been around since the early 1990s, with or without buffer tubes, and while they may have initially garnered a reputation as a range toy or novelty, they’ve come into their own as materials and ammunition have matured.

It seems any time a firearm strays outside its “lane” there are those just waiting to criticize. Pistol-caliber carbines? Why bother? Rifle-caliber pistols? Too slow and inaccurate when compared to full-size rifles. Sometimes, though, you just have to go ahead and do something just because you want to, and that’s a perfectly valid reason in and of its own.

We did learn quite a bit with this build. When originally configured, with a standard buffer, it functioned well with heavier-weight bullets (70+ grains), but struggled with lighter fodder. Often, it would fire a round and fail to pick up the next round in the magazine. Trial-and-error (and talking to co-workers who had already climbed this particular mountain) revealed that the short barrel didn’t yield enough pressure with the fast-moving bullets, so a heavier buffer was in order. Brownells kindly sent in an H3-version buffer that slowed the bolt sufficiently to successfully load 62- and even 55-grain .223 Rem.

At a recent shoot with friends, the pistol was passed back and forth for folks to try, and one thing was certain: the SIG Sauer muzzle brake throws an impressive amount of flame out of an 8.5-inch barrel. It works quite well at dispersing the flash, and down the road, should the pistol be fitted with a suppressor, will make mounting one quite simple. It’s also quite accurate, with 100-yard shots on an 8-inch steel plate quite achievable. The light CMC trigger press and accurate V7 Weapons System barrel certainly contribute to the pistol’s prowess on the range, and highlight why spending a little more for quality components is worth it in the long run.

Here’s the breakdown on components and cost:

Lower Parts:

Anderson stripped receiver
: $57.53 (purchased for $35)
SB Tactical SBPWD Pistol Brace: $299
CMMG lower parts kit: $64.95
Timney Ambidextrous Safety Selector: $65.95
Xtreme Precision Stainless Parts kit: $13.99
Xtreme Precision polymer trigger guard: $7.99
Ergo AR-15 MSR pistol grip: $18
CMC Trigger tactical AR15/10 trigger group: $195.99
Brownells Carbine H3 buffer: $39.99
Brownells Carbine buffer spring: $4.99

Total Lower cost: $768.38

Upper Parts:
Yankee Hill Machine complete upper receiver: $126.25
Brownells Black nitride bolt carrier group: $89.99
Blackhawk Charging handle: $39.95
CMMG M-Lok 7-inch handguard: $169.95
V Seven Weapons Systems 8.5-inch match-grade barrel: $310 (includes pistol-length gas tube and gas block)
SIG Sauer SRD556 Taper-lok muzzle brake: $75

Total Upper Cost: $811.14

Total Pistol Cost: $1,579.52

Now, yes, this is a rather pricey total in the days of sub-$500 AR-15s, but there are myriad upgraded components in this price. An adjustable brace, improved trigger and top-shelf barrel do bring the total cost up, but are well-worth the investment. A less-expensive handguard could save cash, but CMMG’s M-Lok allows accessories to be attached while maintaining clean lines. Besides, this is something you build because you want to, right? Why not have it exactly as you like?


Mauser HSc and the Heckler & Koch Model 4
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