7.62x39 AR build

[blarby]

I think I'm finally ready to take the plunge and build another AR, this time in 7.62x39.

Last time I looked at this however, there were still some serious problems in the x39 AR market, which scrapped the idea.

Anywho....


I have a standard Anderson lower im not doing anything with, which is what stoked the idea.

So.... Lemme have it !

Should I just buy a complete kit ?

Should I piece build it ?

Recommended brands for "stuff" ?

I've built more than a few .223/5.56 AR's, and its boring, to say the least.

One thing that "may" influence parts choice, is I have a 7.62x39 BCG and bolt here in the shop.... but its not mandatory that I use it.

Lemme have it ! Tell me what "you'd" do, and why !


Notes :

Is there anyone offering a milled out feed ramp currently ?

Are there any uppers that already have large gas ports ?

Has anyone solved the broken bolt lugs problem ?

 

[Casefull]

I always buy complete kits. Whenever I price out separate parts it is always more. You can change out parts later on if you want and it can still be cheaper that one part at a time. I have a couple of x39's with anderson lowers and psa uppers. They are great shooters and plenty accurate.

 

[Lloyd Smale]

had a factory bushmaster in 762x39. Fooled with it a lot and still never got it to run a 100 percent. I think I tried every mag made for them. Sent it back to bushmaster twice. Don't get me wrong it ran fair but never a 100 percent. My advice is that if you want a 762x39 get a Ak that was made to run them. If you want a 30 cal ar look at the 300 whisperer or black out

 

[Casefull]

Blarby, you will always hear on the forum about mag problems with the ar in x39. That may have been the case if folks used 5.56 mags but the mag problems were solved long ago. Mine are everybit as reliable for me as are my ar's in 5.56, they sure hit harder though. I use stoner mags from Midway and there are others that work fine also. The ar makes the 7.62 round a better cartridge than it is in an AK.

 

[blarby]

Thanks casefull, thats mighty helpful news!

Just a few more serious issues to go !

I'm thinking that "build" is the way to go, but I could be persuaded otherwise!


Hmm, a PSA upper. Well, if I stopped getting negative feedback from their customers, if might be a more viable option. We'll see.

 

[rbernie]

I've bought six (6) PSA complete uppers in the last year and all of them absolutely met expectations.

You'll want to make sure that you get a 7.62x39 bolt that's set up for Russian ammo (and has a fractionally shorter tail to increase firing pin protrusion as a result). If you reuse the bolt that you have - measure it to see if it's 'built to AR spec' or 'built to work'. You can shorten the collar on the firing pin to increase protrusion, but I prefer to use a shortened bolt.

Also - pay attention to gas system length. The 30cal barrels drop bore pressure a lot faster than the 22cal bores (swept volume differences), so I find that 16" carbine length gas systems are more reliable than middies.

I use the C Products (now ASC) magazines and they work OK. You'll probably want to go with Wolff xtra-power AK magazines springs in them, but it's an easy upgrade.

 

[AndyP]

I have built a few of these things, Here is what worked for me.
1. Geisselle triggers. Outstanding triggers, and have a heavy enough spring to light all of the hard primers.
2. C-products Defense mags. They work great, but seem to need being used about 5 times before they are 100% reliable.
3. LMT bolts. They are $170, but they work. always.
4. I like an adjustable gas block, it won't recoil any more than .556 when its dialed in.
5. Give the rifle a little patience on break in, if you have any hang ups afterwords don't be afraid to remove a little metal on the feed ramps with a dremel.

 

[carbine85]

I was going to build one but changed my mind. What convinced me not to was the talk about the dirty fouling from the cheap ammo and limits on dependable mags. If I did build one I would probably cross over to a gas piston set up.

 

[maxxhavoc]

I'm thinking that "build" is the way to go, but I could be persuaded otherwise!


Hmm, a PSA upper. Well, if I stopped getting negative feedback from their customers, if might be a more viable option. We'll see.

Well, if it helps, here's more positive feedback. Mine works 100% with ASC magazines, and is accurate as well.

 

[blarby]

Well, this is all very positive news.

It looks like things have come quite a long way since the last time I considered this.

Rbernie : on your complete PSA uppers, do they have, or offer, adjustable gas blocks ?

It looks like a complete upper, and a built lower, is the way to go.

 

[rbernie]

No, I've not bought a PSA upper with an adjustable gas block.

Speaking from experience, you are not going to EVER find that you've overgassed a 7.62x39. I would not value the extra cost or complexity of an adjustable gas block for such a build.

 

[Jackal]

I built my x39 rifle using a Radical upper, Aim Surplus BCG and with C Products mags. It's only had issue with Tula ammo, but then again, Tula is the cheapest garbage made. Runs great with Wolf, Barnaul or Golden Tiger.

Most of the bolt lug issues were due to them being made from bored out .223 bolts. Now that we have x39 specific bolts, these issues seem to have mostly gone away.

 

[blarby]

Speaking from experience

And thats exactly what im looking for.

It looks like I can get " the works" from PSA for 499.95, using my lower.

I think thats a wrap.

I'll post when its done !

 

[ssyoumans]

I built my x39 rifle using a Radical upper, Aim Surplus BCG and with C Products mags. It's only had issue with Tula ammo, but then again, Tula is the cheapest garbage made. Runs great with Wolf, Barnaul or Golden Tiger.



Most of the bolt lug issues were due to them being made from bored out .223 bolts. Now that we have x39 specific bolts, these issues seem to have mostly gone away.

I really like my Radical Firearms 7.62x39. I got the entire rifle for $499 from AimSurplus! Comes with 4150 barrel, 16", carbine length gas, and 1 20 round ASC mag.
Only issue I had was with the steel cased ammo as well, getting light strikes. Bought a $8 extended firing pin meant for AR47s from PSA and now I run 100% reliable with all ammo. It measured about .012" longer.

The Radical Firearms upper has the feed ramps milled out for improved feeding.

 

[orionengnr]

Been following this thread with interest, as I recently bought a complete 7.62 x 39 upper from PSA.

Finally got the chance to test fire it yesterday. Worked to perfection with the Russian TulAmmo and an ASC mag I picked up at the Gun Show.

I had no idea what an enjoyable combination this is. Never owned or had any desire for an AK/SKS. I have owned a Mini 30 for 15+ years but haven't shot it much; never found it to be anything special. And I've owned the same 5.56 AR since 1984, but seldom shoot it--again, nothing special.

But I can see myself getting some use out of this rifle. Time to stock up on some ammo before Queen Hillary deems that unacceptable.

Two big thumbs up to PSA.

 

[<*(((><]

I just put together an AR47, I used a Yankee Hill carbine length 16" fluted barrel, AIM BCG with enhanced firing pin, lo-pro gas block Rainier Arms Upper Receiver minus Forward Assist, a Midwest Industries M-Lok 15" rail, and a Compensator for the muzzle device.

Haven't shot it yet, but am excited to do so. I bout 2-10 round ASC mags and 2-20 round ASC mags. Waiting for Cproducts mags to come back into stock.

I probably have ~$500 into it.

 

[FL-NC]

I would never build such a thing. They aren't very accurate, and the AK round just doesn't want to "work" in the AR. Lots of proprietary parts- barrel, BCG, mags. I know, the ammo is cheaper than 5.56, somewhat- but I wouldn't invest the time and treasure in such a project just to launch something a little cheaper. If you want to shoot bulk x 39, buy a clunker SKS and go crazy.

 

[Casefull]

They aren't very accurate, and the AK round just doesn't want to "work" in the AR.

That is simply not true. I have several and there is zero downside. Unless the slightly more recoil from pushing a heavier 30 cal bullet is a problem. It makes the ar a real rifle instead of a hopped up .22. Mine all shoot 1.5 moa or better with good ammo. The mags feed flawlessly. It is like a 30/30 that never runs out of ammo. lol

 

[801sureshot]

You got it right Casefull, I put one together over the holidays this year. Once I worked out the kinks it quickly become my favorite rifle. I had a Maadi back before the Clinton ban and didn't find it all that interesting. I love the 7.62x39 round but the ak platform feels like it is, utilitarian. The ar in the same caliber feels like a real rifle. I've all but lost interest in 556 since. In fact I picked up a cz 527 in 7.62 yesterday as a companion rifle. The asc 20 round mags are 100% in my build. Enhanced firing pin, decent trigger. It's really not that hard to get one to run.

 

[Captain O]

Not an AR fan, but the caliber in the build has my interest. Range limit on a 20" barrel for the 7.62 x 39 is fascinating. I wonder why there is such difficulty in the platform with the Russian cartridge?

 

[wally]

I wonder why there is such difficulty in the platform with the Russian cartridge?

Tapered case in the straight AR magwell. That's the root of the issue.

Its taken a while to get the 7.62x29 AR mags right, Wolff extra power springs (or real AK mag springs) help -- but I still have occasional feed issues with JSP or JHP ammo in 20 and 30 round mags. No issues with only 5 or 10 rounds loaded.

 

[Captain O]

Tapered case in the straight AR magwell. That's the root of the issue.

Its taken a while to get the 7.62x29 AR mags right, Wolff extra power springs (or real AK mag springs) help -- but I still have occasional feed issues with JSP or JHP ammo in 20 and 30 round mags. No issues with only 5 or 10 rounds loaded.

And people wonder why I bought a Norinco MAK-91 NM. The Kalashnikov pattern with a milled receiver works rather well for sporting purposes.

I guess the AK works too, but there always seems to be a problem melding the Eastern-bloc cartridges with those from the Western world.

As Rosanne Rosannadanna said: "It's always somethin'".

 

[maxxhavoc]

Not sure where the rumors of unreliable, inaccurate 7.62x39 ARs came from. Maybe it was a "bad old days" that I missed out on.

I have seen the same rumors, and my $500-ish PSA build doesn't show any of these symptoms. Running 20-round ASC mags I have not had a single feed issue. 2 failure to extract with Tulammo in a dirty chamber, but that stuff does it in my SKS too.

100% with WPA, Which costs 1 cent per round more than reloaded .223.

 

[ugaarguy]

For those interested, Rock River with their LAR-47, PSA with their KS47, and MGI with their modular lower receiver (and probably a few others) have solved the magazine problem by switching over to mag wells that accept standard AK magazines.

 

[TRX]

> ammo is cheaper than 5.56, somewhat

True, for blasting tin cans... but high quality 5.56 is much cheaper than good 7.62x39. And 5.56 Boxer-primed brass is much cheaper, and match-grade 5.56 bullets might as well be free compared to what the AK uses.

I'm hardly the one to say anything against a caliber conversion, but the primary attraction of a 7.62x39 AR was those crates of cheap Combloc milsurp ammo. The American market vacuumed that up, and while there's still some left, the prices have risen to reflect that.

"It would be nifty to build that" is a perfectly fine reason for a conversion, but make sure you're comparing apples and apples when you're considering ammo prices.

- TRX (who built his last AK in .223 because it was cheaper than decent quality 7.62x39)