Letter Re: .300 AAC Blackout Uppers for AR-15s

Hi James,
I read your excellent forum every day, before I read the local paper. In case you haven’t looked at the new .300 AAC Blackout, you might want to take a hard look at it.  

The PDF of a presentation by an AAI executive describes it quite well.

With just an upper receiver swap out, you can have an AR-15 that will shoot through a pretty hefty tree, vehicle panel or door.  I load my own and convert old 5.56  brass into Blackout brass with a single stroke of the press handle. A Dillon electric case trimmer whacks the top 10mm of the casing off as it extrudes from the form die.  I can make a thousand Blackout cases in an afternoon. The new round can launch any .308” diameter bullet.  If I load Winchester 147 gr FMJ boat-tails in it, I can shoot right through a 17 inch diameter cedar tree every time. Recoil is mild, slightly heavier than the 5.56. Noise is far less, especially if fired from a short barrel (compared with the ear-splitting 5.56).  My teenaged girls love shooting it, unlike the M1A.  It fits them, costs little to reload, and generates about 71% of the power of a full house 7.62 NATO.  It’s a 300 meter cartridge in 147 grain variety, or a 460 meter round in 110 gr or 125 gr format.  The Barnes TAC-TX and the Sierra 125 gr Match King are Blackout-specific…totally redesigned to squeeze maximum downrange performance out of the round. Factory ammo is available from Hornady, Federal, and Remington. I like the Remington 115 gr ball round of all the factory loadings. Even this OTM load will defeat a 9 inch tree, more than any loading in the 5.56. Haven’t tested the Sierra 125 Match on a tree yet, but it does about 12 inches of plywood, shot into a stack, against the edge of the grain. Bullet stays intact! Bends into a banana and yaws immediately. With pulled .30-06 AP bullets at only 1,680 feet per second, it waltzes right through 29 inches of tree (it may penetrate more, but I haven’t found a fatter tree yet!). I’m learning that velocity is not everything.

The Blackout uses the original 5.56 bolt, carrier, magazines…you buy nothing but the new upper. Swaps in ten seconds.  So, you get the handiness of the AR rifle, which fits small shooters and girls very well….with a round that hits like a hammer.  Spec Ops units are using it right now, as well as some enlightened LE outfits.  I showed it to my local police, and they were either bored (most patrolmen) or they jumped on it (SWAT people).  Most patrolmen would rather have a new ball point pen than a new gun.  None of the locals were in any way hostile to armed citizens, with most quite supportive. Another good reason I like living in Utah–we have mostly good cops.

If you run low on Blackout ammo, swap the 5.56 upper back on and go. Two useful calibers (well, one, anyway…) on one platform. Produces 16% more energy than the Soviet 7.62×39.  Zero muzzle flash, since it uses pistol powder (H-110/W296). At 100 meters and beyond, it exceeds the energy of the .30-30 Win. It is wildly popular for feral pig hunting in Texas.  About half of my shooting friends have already converted at least one AR over to the Blackout.   I recommend the Advanced Armament Company (AAC) upper, as they pioneered it with Remington Defense, and build uppers for serious users (Special Ops) and do everything to military specifications. Theirs feature generous clearances in the chamber dimensions so they will run with dirty ammo, hot barrel, adverse conditions. A “match” chamber is just for players and hobbyists. The best place to buy one is through Bulls Eye Indoor Range in Lawrenceville, Georgia. Ask for Jeremy, their Blackout specialist. Factory ammo is available there, too.  Since it is just an upper, there is no paperwork to fill out unless you want to build a with a short barrel. [Which requires a $200 transfer tax in the United States.]

Some cling to the 6.8 SPC for an AR upgrade, but the 6.8 SPC will not munch through a tree like that .30 caliber can.  Pulled AP bullets bore through 3/8” plate with boring regularity. Rolling my own keeps me off the streets. While recovering from heart valve surgery, I made about 16,000 rounds (television only gets you so far!). I nagged all of my shooting buddies to try this round about a year ago, and now nearly all of them have converted.  I have a source of formed brass near Salt Lake, and I am picking up some 28,000 of them Saturday (not all for me!)  With the shortage of 5.56 now, I have stopped chopping my own brass.

Thanks for all of your excellent work! God Bless, – Paul S.

JWR Replies: Both 6.8 SPC and .300 Blackout do have their merits. But I must warn readers that they need to get their primary rifles squared away in standard calibers first. If you can afford it, then it is fine to get a spare upper for your AR chambered in an exotic cartridge. But be sure to stock up with plenty of ammo, since any exotic ammo will be very difficult to find in a post-collapse environment. Ditto for specialized magazines, to match. (The 5.45 x 39 and 6.8 SPC rifles require special magazines, but the .300 Blackout does not.) Most importantly, always retain your rifle’s original upper, magazines, and ammo so that you can reverse-migrate to 5.56mm NATO!

My personal approach for AR-15s and M4geries has been to keep them fairly standard. I did, however, but one spare 5.45x39mm upper receiver group for one of my M4s. I did so to take advantage of the profusion of Russian military surplus 5.45 ammo that comes in “spam” cans. I was able to acquire five 2,080 round cases (10 spam cans) of this ammo for about the same that I would have paid for 2,500 rounds of 5.56mm NATO. And since I bought all of it at local gun shows, I didn’t have to pay for shipping. This upper has provided some very inexpensive target shooting opportunities for my family.