Questions about 7.62x39 uppers on AR15s for people who own them.

[KevininPa]

Hello all. For the people who own/built 7.62x39 ARs.

Which upper did you choose?

What mags work the best for you?

Did you encounter any/many problems with your build?

My current situation is that I am going to build an AR. I like the 7.62x39 round. Especially since my shooting will be in the close to medium range. My lower came from 80 per cent. A friend of mine who has been building and shooting ARs uses these. The lower kit I have is from PSA. The lower is set up for AR mags. I'm planning on using twenty rounders just because I find them to be handier for me.

So there the bulk of it is in a nutshell. 223 people need not apply with opinions. 7.62x39 people,......please, intrigue me!

 

[<*(((><]

I built/assembled mine from scratch. Much of the internet lore about x39 AR’s being problematic is so 1990’s-2000’s.

-Get a reputable bolt (AIM Surplus, LWRC, LMT). If on a budget I would go with PSA.
-Enhanced firing pin (more protrusion for reliable combloc ammo primer ignition)
-I prefer carbine gas for dirty ammo and a H2 buffer to keep the dwell time up.
-CProducts magazines 10,20 and 28. I don’t like their 30’s because the curve is really exaggerated over the 28’s and they don’t fit in a lot of STANAG pouches.
-Pay attention to feed ramps (this has probably been fixed by now by most x39 barrel manufacturers) there should be little to no wall between the two ramps this will help with feeding the heavy taper cartridges.

Most of what I’ve said above is commonplace anymore for AR47’s, but these details were at one time what made or broke an AR47.

My AR47’s critical parts is comprised of the following:

16” Yankee Hill Machine Diamond fluted carbine has
AIM Surplus BCG melonited (LMT bolt for backup)
H2 buffer standard mil spec buffer spring
LaRue MBT trigger

Another crucial piece is a picture of the groups you shot with it to show your friends what your “junk commie round” can do in a good platform.

 

[someguy2800]

I built mine as well. I used a bear creek side charging upper receiver and BCG and an anderson lower. I use 10 round C-products mags and have never had a single malfunction ever.

 

[M1key]

You almost can't go wrong building it yourself though. PSA sells a nice complete upper. Spare bolt is a good idea and ASC 10, 20 round mags work very well. You can shoot whatever ammo you like but I prefer either brass cased ammo or my brass reloads.

I own a Colt carbine. Here it is with a red dot.



M

 

[spazzy]

Mine is a PSA lower with the upgraded 2 stage trigger and a bear creek arsenal free float upper. I use 5 and 20 round asc magazines. The 30 rounders stick out too far for my tastes. I have a cheap tasco world class 1.5-4.5x32.

I shopped for 6 months or so and bought things on sale, total cost is about 475-500, with optic and magazines if I remember right.

Zero problems so far after a few hundred rounds.

It really likes the pmc bronze brass case ammo. About 1 inch to 1.25 groups at 100 yards.

The cheap steel case tula or monarch groups 2-2.5 or so. But I'm usually not trying for max accuracy when blasting the cheap stuff

 

[303 hunter]

Mine uses a 16” ARP barrel and ARP Superbolt. I lap my upper receivers to make sure everything is properly aligned. This is especially important with 7.62x39 because of the thinner bolt lugs. Proper alignment of the barrel and receiver means less side load on the bolt.

 

[<*(((><]

@303 hunter

I too, lap all my upper receivers. Glad you mentioned that, I always forget to mention it.

 

[KevininPa]

Good stuff coming in everyone. I'm soaking it all in. As for more background, I know nothing about ARs. Have fired a few friends. Just felt it was time to dive in. After all, if so many people want to take them away from us, then you know that they have to be fun!

I do have friends who will help me learn more about these, so I won't be going into this blind.

 

[H&R Glock]

My complete upper was on sale at MidwayUSA for $199 (ARStoner Brand) and I stuck it on a cheapie PSA lower. Runs fine with no malfunctions. The 30 round mag is rather unwieldly , but lesser magazines are pricey. A 15 round mag is my next purchase.
BTW a standard AR mag can be loaded and fired with about 4 rounds of 7.62, but I haven't tried to load more in them.
It digests all manner of surplus and red ammo with no problems. I have never needed a spring kit or firing pin stretcher with it.

 

[NR53]

The first one I purchased was a SOTA, 16" stainless, carbine gas .308 bore. Broke a bolt but replaced it with a Red X bolt, and has been fine since. I reload for it and use .308 diameter bullets. It likes 125 grain TNT, 125 grain sierra tmk, and Federal 130 gr MK319 bullets(very impressive).

Second one I built using a Faxon 16" barrel, mid gas, .310 dia QPQ . It has a faster twist 1:8 and seems to like the heavier bullets. Aim surplus BCG

Third one I built using an ARP 16" barrel, mid gas, melonite, Aim surplus BCG,

Fourth one was a 10.5" Faxon pistol, carbine gas, side charge BCA. Wow, that thing is loud, even with a linear comp. LOL

Last one was with an ARP 16" barrel, mid gas, side charge BCA.

All except the first one have lapped upper receivers. Handguards are either M LOK or carbon fiber. ASC 10 rounders are what I use mainly. Firing pins are the longer x39 type. Aim suplus comes with them, if not I get one from Red X, have had good luck with them. I mainly shoot reloads through these although they will handle steel cased Russian stuff just fine. I prefer mid gas in 16" barrels, and run standard carbine buffers and springs in all of them. I put 2 stage triggers in all of them( personal preference YMMV)

Other than the bolt breaking on the first one, I've haven't had any problems whatsoever . Took a nice 11 pt buck at 175 yds with #2. Have shot many coyotes, armadillos,etc with the rest. If you reload, CFE BLK is the powder to use.
Good Luck

 

[<*(((><]

@NR53 1:8 Faxon you say. Hmmmm…do you have a suppressor, have you shot it suppressed? Have you fired any subsonic velocity rounds in it?

The next x39 I put together will be a pistol 10.5" with a fast twist to allow for some subsonic use as well as supers.

 

[NR53]

@NR53 1:8 Faxon you say. Hmmmm…do you have a suppressor, have you shot it suppressed? Have you fired any subsonic velocity rounds in it?

The next x39 I put together will be a pistol 10.5" with a fast twist to allow for some subsonic use as well as supers.

No, I do not have a suppressor, and have not shot subsonic rounds. Sounds interesting tho. And yes, both the 16 and 10.5 Faxon barrels are 1:8 twist.

 

[Ed4032]

I started with a PSA complete upper and put it on an ar lower that I already had. Ran like a sewing machine. Then I changed many of upper parts and got a dedicated lower. Still runs like a sewing machine. Fun fun fun

ASC are the only mags that I use

 

[boom boom]

ASC mags for the higher capacity 20 or the less common 28. Even the Stoner cheapos work fine for the ten rounders.

Get some extra stripped bolts as spares. Keep spare extractors and parts around if you want to shoot steel cased.

I went with a 16 inch bull (socom type) barrel profile from somewhere like Midwayusa or Brownells, been too long with a bog standard A2 type .30 caliber flashhider. Carbine length gas system and toolcraft bolt carrier, extended firing pin (useful for hard military primers in 7.62x39), bolt came from black rifle arms. Upper and lower were Aero Precision and a fixed Hogue AR Stock with a rifle buffer and spring. Shoot about 1.5-2 MOA @100 yds with 4x fixed scope from a rest with good ammo, a bit worse with Russian fodder (except wolf for some reason).

 

[ApacheCoTodd]

Colt 20" & Colt.

Never a missed beat, never a missed target.

Todd.

 

[sevt_chevelle]

I built mine.
BCM upper, barrel from Satarn/Liberty whom supplies Brownells with their premium brand barrels. 16" barrel with carbine length gas system, .310 bore, other makers are using .308 dia.
Extended firing pin.
Vltor A-5 buffer system with a 5.3 oz buffer.
C Defense products mags, have a better reputation then ASC mags. Mine have been flawless.
I shoot nothing but cheap steel cased ammo out of this thing, it has been about 1.5ish moa at 100 yards.

 

[ercnjasmine]

Anderson lower with a2 stock, bca side charge upper with their stainless barrel as well. Hogue overmold handguard and a simmons 3-9x. Have an extended length firing pin from red x on the shelf that ill put in soon. I use c products 20 round mags and have had no issues.

 

[someguy2800]

Anderson lower with a2 stock, bca side charge upper with their stainless barrel as well. Hogue overmold handguard and a simmons 3-9x. Have an extended length firing pin from red x on the shelf that ill put in soon. I use c products 20 round mags and have had no issues.

That’s sounds awfully familiar minus the handguard

 

[Gumby0961]

I love my x39, started with stoner upper from midway. I use an aluminum psa 80% lower with Giselle SSA-E trigger, tried a timney drop in but the springs were to weak to reliably function. I also use the enhanced firing pin, but modifying the stock pin is very easy by taking a few thousandths off the pin stop works.
I use the c products 10 round magazines , I had to slightly bend the "ears" up at the front of the mag to reliably feed. I shoot the tula steel case hollow points for plinking and hand loads for accuracy. I use a 3x primary arms prism scope which is to me is perfect for the range of the 7.62 cartridge. This caliber is my favorite for economical, blowing stuff up fun. Good luck with your build.

 

[GE-Mini-Gun]

Not mine, but I shot the crap out of it. Buddy had an M16 with a Model 1 Sales 10.5” upper with 30 round “Frankenmags” and some cheap Chinese 75 round drum mags…they all ran great. The only issue he ever had with the gun was the bolt…he’d break a lug off a couple times during the shoots…this sounds like a lot and it probably is, however he would do mag dump, after mag dump, after mag dump…he abused the crap out of the gun, but it never stopped running. This was 10-15 years ago and he has since sold the gun…no idea if the bolts are better now of the same.

 

[KevininPa]

Sounds like ASC and C Products is the way to go for mags. I found with my Saiga that I'm fond of ten and twenty rounders. And the only .223 I have is a Remington 7615 pump. A thirty is sort of a joke on that. I'm thinking that I might buy a complete upper and upgrade some parts as need be.

 

[ercnjasmine]

That’s sounds awfully familiar minus the handguard

View attachment 881284

 

[maxxhavoc]

I went with a PSA lower, PSA upper. No issues, a lot of fun to shoot. I also use ASC or Cproducts mags with no issues. I will order another bolt or 2..not a bad idea.

Only issue I have is with shooting Tulammo. I get stuck cases shooting that, or after shooting that. Brass case, wolf, or bear of any color has been fine in the AR.

 

[rdnktrkr]

A friend built one, BCA upper and PSA Magpul lower, iron sites, he uses 20rnd mags and it shoots every thing we've tried. He hasn't had good luck with the 30 rounders. He dropped a doe this yr at about 80yrds from my blind while setting on his 4 wheeler. It kicks more than my 6.5 grendel.

 

[bfoosh006]

For all those with 7.62x39 AR's.. any accuracy results you could post up ?

Both with less expensive Com-Bloc ammo and better ammo ( Hornady )