There’s a good chance you’ve heard the old Vietnam War stories that the Viet Cong could fire our 5.56mm M16 ammo in their AK-47s, but we couldn’t use their 7.62x39mm ammo in our M16s. I guess it made for a good story about the adaptability and resourcefulness of the VC, but science disagrees. It’s physically impossible to run a 5.56x45mm round in a 7.62x39mm chamber reliably or safely. It’s been tested and it simply doesn’t work.
The idea of being able to use your enemy’s ammo has some merit though. In the early 2000’s U.S. Special Operations troops used limited numbers of Knight’s Armament Company SR-47’s, which were basically M4’s chambered in 7.62x39mm that used AK mags.
What if the US had done similar back during the Vietnam War to counter those pesky VC using magical AK’s that reliably fed both 5.56 and 7.62 rounds equally? Thus the 7.62×39 Commie Commando was born.
The Commie Commando
Since I was going for a Vietnam era vibe, I decided to base my build on the XM177E2 rifle. I had already built a pretty accurate 5.56mm clone a while back so I used that as my reference for a 7.62x39mm build.
I had an A1 upper with tear drop assist in my parts bin already that I had picked up in trade somewhere. All it needed was an ejection port cover and rear sight kit from Luth AR. I did cheat and swap out the A1 rear aperture for an A2 aperture. I much prefer the bigger A2 rear and if I’m not building a direct clone I always opt for the A2 rear over the A1.
I picked up an E.R. Shaw 11.5-inch barrel with front sight base from Model 1 Sales along with a gas tube, barrel nut and slip ring. I used a later style Delta ring rather than the early flat one. The E2 XM177’s used one so I figured that was fine. Plus the flat ones suck and I only use them if necessary for the clone build. For handguards I used the excellent OEM CAR ones from Echo Nine Three. To round out the barrel I used an extended Commando/XM177 style flash hider from KAK Industry.
I already had a chrome KAK bolt carrier around that I picked up during the Christmas sales. I bought a 7.62x39mm bolt from them when I got the flash hider and picked up an enhanced firing pin as well. I used B. King Firearms for my lower parts including the retro two position buffer tube and an H3 buffer. I had a rubber covered aluminum CAR stock as well from Doublestar. In theory it was a blem, but other than being a little tight on the buffer tube at first I didn’t see any other issue.
For a grip I used my favorite shiny B5 Systems LS2. Yeah, I know that’s totally out of era for a Vietnam-ish build I still like the way they feel and I thought it looked good on this set up.
Schrodinger’s Lower
I wasn’t cloning anything in particular, but I did want to keep a retro vibe so I decided to use an A1 lower as well. I didn’t have one on hand but when I ordered my Cat M4A1 lower from Bad Attitude Department I decided to take a shot at their Schrodinger’s Lower offer. These are basically lowers have some cosmetic issue, but are fully functional. It might be an off finish, an engraving error, or even a test lower for some product that may or not be issued later.
If you have kids, you’re probably familiar with the blind box concept. Basically you buy something, usually a toy figure or similar, knowing it’s part of a series, but you don’t know which one you’re going to get. The kids think it’s fun to be surprised with what you get, or disappointed that you got a crappy one or a double of something you already have.
With toys you pay for the privilege of being surprised by a random item. With BAD you actually get a price break. The Schrodinger’s Lower is only $59.95 as opposed to $139.95 for most of the A1 lowers. It’s a good deal if you aren’t picky about what you get, and the surprise of seeing what you end up with is kind of fun. I’m not worried about duplicates, and any functional AR lower is a good by me. Honestly, I’ll probably add one of these on any time I order from now on, just because.
So, what did I end up getting? I actually got a Korean M16A1 lower with a burnt bronze finish. It was marked “Engraving Sample” on the grip tang. I actually had been thinking about getting one of the Korean M16A1 lower for a full Korean clone build. Still, I needed a lower for this 7.62 build so I decided to stick with the plan.
The bronze color was actually pretty cool, but I needed black to go with the rest of the gun. That was an easy enough fix with an application of Norrell’s Moly Resin in “Grayish-Black Colt Flat” and a quick bake in the oven to set the finish when my wife was at work.
Since this gun never actually existed as an issue item, there was no wrong lower to use. With that said, I thought the Korean lower with it’s Korean markings was pretty neat for a build with fake Southeast Asia provenance. Maybe my alternate reality War Department contracted these special issues rifles from Korea due to the US supply channels being backlogged? There is no caliber marking either, which is actually good in my opinion. You don’t have a 5.56mm marked gun with a 7.62mm chambering.
The Whole Package
I waited until January to file for my Form 1, taking advantage of the $0 Tax Stamp. It took about six weeks for approval, but my combination of lower manufacturer and caliber wasn’t in the database already either. Of course the whole NFA is unconstitutional anyway, so let’s hope 2026 is finally the year that at least knocks out the SBR and suppressor provisions…or better yet, the whole thing.
My 7.62 Commando is 33 inches overall with the stock extended and 29.5 inches with it collapsed. That’s the same as my 5.56mm XM177E2 clone. The 7.62 weighs 6.9 pounds with an empty 20 round magazine, the XM177 is a bit lighter at 6.3 pounds. The main difference is the barrel profile. The 177 has a pencil profile barrel whereas the 7.62x39mm barrel is a heavy profile. It’s still reasonably light and quite handy.
I had some short 20-round, and big 28-round Duramags on hand already from my other two 7.62x39nmm ARs. Other than that, I rounded out my kit with a Chinese AK chest pouch and a Vietnam era nylon M1 carbine sling. I used a GP Utility Strap and some paracord as a sling on my XM177 but wanted something different for this build and the M1 sling worked well and looked appropriate for the Commie Commando.
Same Size, More Punch
The Commando is a pretty close twin to my 5.56mm XM177, but it packs a decent jump in punch. You move up to a much heavier .30 caliber bullet (okay, .31) and a bit more overall muzzle energy. The 7.62x39mm is less adversely affected by the short barrel too. With the enhanced firing pin I can run the harder primer import ammo.
It’s just a shame that the heyday of cheap 7.62x39mm is over. I’m still sitting on a stash of old 7.62x39mm, but I’ve been running through it. A quick look online just now is showing 20-round boxes of 5.56 going for around $10 and the same quantity of 7.62x39mm running $12 to $13. Still, it’s available, just not at discount prices like the old days.
I don’t think I’ll be putting an FRT on this build though. It’s hard enough on the wallet ripping through mags of 5.56mm. Unless something changes, my third selector switch marking is just for looks on the Commando.
I’m pretty happy with this build overall. It’s certainly a functional rifle, but I like the “what might have been” aspect to it the most. Just like Spec Ops troops did in Afghanistan in the 2000’s this could have been done during Vietnam for troops operating behind enemy lines. If nothing else, I finally have an American rifle that uses that damn Commie ammo.