A few thoughts on why a SBR or AR pistol is a good idea. It is a solid plan to have a reliable carbine on hand for self defense as well as to bring joy to the firing line. In this day and age it does make sense to keep more than your defensive handgun in proximity to your person.  The thing with carbines, though they offer a smaller footprint than rifles, they are still large and can be difficult to wield in tight quarters. Enter the short barreled rifle, or SBR. Now, I know there is the option of the AR pistol, and I do not discount that option whatsoever but we can run into some legal issues if one were caught shouldering the AR pistol. I know what many are thinking but in the interest of being above board we will only talk about shouldering the registered SBR.

It is a bit of a pain in the ass getting a short barreled rifle. It takes applying via a Form One or Form Four to the BATF for the $200 tax stamp and then the wait for the tax stamp begins. While the wait sucks, once you get the stamp it is well worth it. Now there are a few restrictions on the SBR, such as the same laws that apply to rifles apply to it when transporting. Additionally, as with any NFA item, if you are transporting across state lines you must notify the BATF. Since you have a more traditional stock on the SBR, you can use a collapsible stock for a much better fit to your person as well as totally collapsed it has a much smaller footprint than the AR pistol.

In my opinion, all things considered, the short barreled rifle has some advantages over the AR pistol. That brings us to the Barnes Precision Machine SBR. BPM has a solid reputation as a quality manufacture building various types of AR style rifles and pistols. You can read my review of  the Patrolman’s Rifle in 300 Blackout by following this link  and the AR pistol in 300 Blackout by following this link. So, I am familiar with the Barnes Precision Machine rifles and pistols. The SBR I am working on has two uppers, both are seven and a half inches but one in in 5.56 x 45 and the other is in 300 Blackout. Both have good characteristics so I am going to cover both in this review.

As rifles go, the 300 Blackout is an excellent close quarters combat round and works great out to about 200 yards depending on the round you are using while the 5.56 is excellent CQB round it surpasses the 300 Blackout past about 250 yards, depending on ammunition, and is damn deadly out to 600 yards with the right person behind the gun. When you drop back to the short barrels you loose velocity but gain maneuverability, as we all know there is no such thing as a free lunch.  You can reference my 300 Blackout ballistic test from a sixteen inch carbine by following this link.  From my initial experiments fourteen to sixteen inch barrels in 300 BLK are basically the same.  When you drop back to seven and a half inch 300 BLK you do lose an average of a couple hundred feet per second which translates into a couple of inches less ballistic gel penetration. Still in the grand scheme of things, that is not a huge difference. For the 5.56, you can read my ballistic test comparing a sixteen inch, eleven and a half, and a seven and a half inch barrel by following this link.  Ammunition selection for the 3oo BLK is not quite as critical as the 5.56 in the short barrel platform. You have more options with 5.56 in barrier penetration, it’s cheaper to shoot than the 300 BLK, and it is a bit easier to come by.

Now we’ve got the technical aspects out of the way, on to the short barreled rifle, onto the Barnes Precision Machine CQB SBR


Top is the SBR with the 7.5″ 5.56 upper and you see the 7.5″ upper, with the black handguard. pictured below. For this short of a barrel I recommend either a vertical or angled foregrip.  Note, the muzzle device on the 300 BLK upper is a 90 tooth AAC QD mount for the SR-7 silencer. Though very hard to do, a 300 BLK round can be chambered in a 5.56 chamber. Since the 300 BLK is based on the 5.56×45 case, the only thing different is the barrel. If a 300 BLK round was chambered in a 5.56 chamber and the shooter got aggressive with the forward assist, it could be possible to force the .30″ bullet back in the 300 BLK case enough for the bolt to go to battery. The 300 BLK would have to be a light charge so there was room in the case for the bullet. Though difficult to do, I elected black handguards on the 300 BLK upper and used black magazines for the 300 BLK rounds.


Bolt release and safety are in the tradition positions, they are well serrated for a firm purchase.


Magpul six position collapsible stock.


The BPM handguard, with threaded holes for mounting Picatinny rails. BPM is now offering M-Lok on their handguards as well. There are provisions for a QD sling attachment.


Traditional magazine release and forward assist. Notice, the Nickle Boron bolt carrier group. The trigger is an upgraded Geissele G2s trigger with a bit of take up, breaking clean at 4 1/2 pounds with just a touch of overtravel. Definitely worth the upgrade.


The butt stock fully extended. The rifle comes from the factory with Magpul flip up sights. While many manufactures are electing to leave off sights, I am thankful BPM did not.

Initial Range Trip 

Not counting the ballistic test, the seven and a half inch short barreled rifle is a lot of fun to shoot. Fun is great and all but it takes a lot more than fun to sell the SBR. When going that short I wondered if reliability or parts and wear would be affected. What about accuracy or terminal performance? You can reference the ballistic test and learn that though terminal performance did suffer a bit with proper ammunition choice the shorter barrel is not an issue. After going through a couple hundred rounds of 5.56 and 300 BLK while shooting some B roll the SBR is proving to be reliable. Still 100 yard groups and more rounds downrange is needed to form a solid opinion.


Click on the chart for the accuracy test. Both uppers were shot with 3 shot groups from a rest at 100 yards using iron sights. In my opinion that is not bad at all for such a short barrel and my eyes.

Second Range Trip 


After some 600 various rounds, without a failure, in some less than ideal circumstances the little SBR that could proved to be reliable. It should be noted the 208gr Hornady 300 BLK subsonic would not cycle the bolt without a silencer installed. This was typical with several other 300 BLK rifles of various manufactures. After an afternoon at the 100 yard line with both uppers accuracy was more than acceptable. Running the 300 BLK upper suppressed did not affect accuracy or reliability. With subsonic ammunition the suppressed 300 BLK was pellet gun quiet. As far as accuracy and reliability, as expected, there was no difference between SBR and the AR pistol.  After the mud dip I did field strip the upper and there was no noticeable wear on the Nickel Boron bolt or carrier group. The only real disadvantage, other than the $200 tax stamp on the SBR, is report. The 300 BLK was not bad but man that 5.56 was plenty loud. Truthfully with the 5.56 that is to be expected but still should be well noted. The compactness of the BPM SBR in 5.56 lends it well for home or personal defense, though if using for home defense I would encourage adding a silencer. Though it would not be 300 BLK quiet it would be more tolerable without hearing protection.  Not that I would want to spend the day shooting a suppressed 5.56 if you needed to deploy it in a hurry I doubt you would have time to get your ear pro on. Or you always have the 300 Blackout option which suppresses really well. You also have the option of buying an AR pistol, submitting a Form 1 to the BATF to convert it to a SBR. While you wait you still have the pistol to enjoy and can convert it when your stamp comes in. I know NFA rules suck out loud, but once again that is where we are. So when or if something changes we can go from there but for now we all have to suck it up. Don’t let the heavy handed laws discourage you from owning NFA items though. To sum up, I am happy with the BPM CQB SBR with either 5.56 or 300 BLK on reliability, durability, and accuracy. If you are in the market for an AR-15, SBR, or AR pistol it is worth stopping by Barnes Precision Machine and see what the NC company has to offer.


Barnes Precision Machine SBR CQB

Caliber: 5.56×45 and 300 Blackout as tested

Barrel length: 7.5″

Overall length: 24 1/2″ collapsed 28 1/4″ fully extended

Weight unloaded: 6 3/4 pounds

Trigger pull: 4 1/2 pounds

  • Mil Spec 7075 forged upper/lower.
  • Upper receiver, lower receiver and handguard hard anodized to Mil Spec Type III specifications.
  • All BPM Inc. lowers feature adjustable tension screw and detent retention set screw for rear takedown pin detent .
  • Pistol length gas system
  • 7.5″ 416 stainless steel barrel blanks. CNC machined in house with 5.56 NATO chambers.
  • BPM Inc. PSFFRS Ultra-lite Extreme 7″ Handguard complete with quick detach sling swivel inserts. (FDE Cerakote)
  • Every BPM rifle ships with Patriot AR Case with custom high density foam inserts, Users Manual with Warranty and one Magpul PMAG


Barnes Precision Machine 

Stillwood Ammunition 

Defender Ammunition

Gorilla Ammunition 

By Hunter Elliott

I spent much of my youth involved with firearms and felt the call early on to the United States Marine Corps, following in my father's and his brother's footsteps. Just after high school I enlisted and felt most at home on the rifle range, where I qualified expert with several firearms and spent some time as a rifle coach to my fellow Marines. After being honorably discharged I continued teaching firearm safety, rifle and pistol marksmanship, and began teaching metallic cartridge reloading. In the late 1990s I became a life member to the National Rifle Association and worked with the Friends of the NRA. Around that time my father and I became involved with IDPA and competed together up until he passed away. I began reviewing firearms for publications in the mid 2000s and have been fortunate to make many friends in the industry. Continuing to improve my firearms skills and knowledge is a never ending journey in which we should all be committed. I am also credited as weapons master on a few independent films.

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