I have a stripped lower and upper sitting in my safe that has been there for the past 6 months.  I'm thinking about doing a 7.62x39 build, should I?  I'm on the fence and would like to hear from anyone that has an AR chambered in 7.62x39.

I don't hunt so it'd be for range and HD use.

I already have two ARs chambered for 5.56 and one in 6.8 and I have an M1A.

So, it's nearing completion. I took the barrel up to my friend's house so he could weld up the brake. Although I drilled the holes and made the pin. We did screw up, for some reason the brake turned so it's just a bit off center of where I wanted it. Considering this is the first brake pin and weld I did I'm not too worried about it being turned a bit. I used an 1/8" drill bit that I cut down for a pin.

</a>" />

I'm still waiting on some small parts to come in... Mainly the bolt catch pin, spring and plunger. I still also need a front sight. That's my friends carry handle on there. I also might change the ACE Skeleton Stock out for an A2.

I'm using an ARP brake that's the same diameter of the barrel so I can pull everything off. It's also got an Adams Arms Piston kit.

Absolutely! I built 2 earlier this year, love them. But don't go in blind. They can be challenging.

http://www.ar15.com/forums/t_3_121/679040_Let_s_review_my_2_7_62X39_AR_builds_after_a_day_at_the_range_with_them_.html


http://www.ar15.com/forums/t_3_121/673673_Can_we_talk_7_62X_39_firing_pins__mags_and_other_improvements_.html

My friend, you've have asked a question that I have been waiting to answer. I did a ton of research on ARs chambered in 7.62x39. I was iffy due to all the horror stories out there. I decided to take a chance and purchase a Windham Weaponry SRC in 7.62x39. Gun runs like a rapped ape. I was originally just going to get one of their uppers but I decided to get the complete gun. I absolutely love it. Windham has a deal going on right now (20% off). You could probably get their 7.62 upper for a discounted price. I contacted Windham before I got the rifle and the tech told me that they had addressed all the problems associated with 7.62 ARs. Proper sized gas port, larger feed ramps, protruding firing pin for steel cased ammo. All I have shot out of mine is cheap Tulammo. It eats it up.

My thinking is no. Go .300blk because you'll never have to search for mags or company specific small parts if something breaks.

If you want access to 762x39, the ak route gives you options and its fun to branch out a bit.

Yes build it
or
PSA has  AR47 upper with BCG for $319  http://palmettostatearmory.com/psa-pa47-16-7-62x39-upper-w-bcg-and-charging-handle.html
Mine runs so great I sold my AK

As tempting as it is, I'm thinking a better route may be the Sig556 R (I think it is) chambered for the 7.62x39.  

I own one in 5.56 and so far it seems like a fantastic rifle.

I'm in the market for a 7.62x39 upper myself. With the cost of x39 (these days), it's a no brainer.
x39 requires a different barrel (as does 300BO), and the cost of a few mags and x39 bolt/FP is FAR cheaper than having to buy 300BO ammo. After a case of x39 ammo (vs 300BO) you'll have already paid for those mags/bolt/FP and will remain in the + from there on out.
The only thing that's held me back is I can't find a 16" x39 middy w/ standard hand guards/A2 FSB (yet) for a reasonable price (I have zero interest in FF'ing a x39).
Besides the upper, there a a few good deals out there:
CPD 28 round mags (seem to be the only seriously reliable option out there currently, and they fit in M4 mag pouches)
AIM nitride x39 carrier/bolt/FP.
Wolf poly 7.62x39 (it's VERY reasonably priced currently, and it's worlds better than crappy inconsistent Tula). Cases average just over $200 currently.

So.... to answer your question... yes, DO IT.

I've read the horror stories too, which is why I'm on the fence on building it. I see Green Mountain has a 7.62x39 barrel but it's got a .750 gas block, is the gas hole going to be too small?

I have a radical firearms upper which I love it runs great. Agree with the poster who said wolf is more accurate than tula.  Save your pennies and buy Golden tiger its not that much more and it shoots honest 1.5" groups out of my upper.  Don't know if I would build one unless you are simply looking for a challenge, a complete upper seems to be the way to go.  I haven't heard many horror stories about complete uppers its normally some part gun someone put together and yes .750 seems a little small to me.

3/4" is standard gas block size.

Built one back at the beginning of the year and after a small bit of work I have a very accurate, mild shooting ' thumper' with great reliability. Found that mine prefers Privi soft points for best accuracy with Yugo M-67 military right behind those in accuracy. Going to try some of the newer CPD mags before too long, but having no problems with the ASC mags with the front trimmed out.


Bird

7.62 AR Parts,
I went with the RedX BCG complete.
Enhanced 1
Enhanced 2
Enhanced BCG

Of course the bolt is as important as the pin. Because of the larger rim diameter of the 7.62 case, the bolt body has a larger diameter hole in it thereby making the wall thickness of the bolt thinner (and thus weaker) Proper material and heat treating is important and why I decided to go with RedX because they seemed to know what they were doing, time will tell.

Here is an email from C Products Defense. Although I have not cycled a lot of ammo thru my setup I was impressed with CPD's knowledge and response to my questions.


Got my CPD  mags at Brownells

I've heard people say that the issues have been worked out.  I wouldn't touch an AR-15 in that caliber, but that's only because the Colt 6830 I sold wouldn't run with anything but the factory 5-round magazine.  That was many years ago, and do believe the feed problems have been worked out.



If it was me, and I wanted a 7.62x39 AR-15 to shoot up a lot of cheap plinking ammo, I'd buy a frankengun designed for the cartridge.
If you want a .30 AR-15 cartridge that is ballistically equivalent with supersonic ammo, with more and better bullet choices, and works really well in a suppressed SBR configuration, get a .300 BLK.
Mag compatibility with your 5.56 is a bonus.





 

I have had the most issues with the three X39 AR's I have assembled.
And the Colt barreled one, was the worst to get running.

That's "the" barrel for us builders. Great barrel. Fwiw, I built my x39 for one reason, to run cheap steel cased ammo. I have a 300, 50beo also, those are reloading only for me. I've chrono graphed the standard black box Tula right at 2400fps from this barrel.

I have a GM-M7 barrel from Green Mountain and its a very accurate barrel which is why I was looking at the one in 7?62x39.

I had also considered building a .300 BO upper too but since I'm in a communist state I can't run suppressed or short barrelled which is part of the reason I went with 6.8 for my last build.

I built one, and it is my favorite rifle.  Polish the feed ramps with a dremel. Grind the edge of the mag body right in front of the follower. They rifle will be great.

i built a 16" and a 7.5", they both run great with cheap commie ammo. use cpd mags

Unless you are a reloaded who has a progressive press 300 BLK is just to expensive for plinking and their are better options for HD and hunting.  The x39 will do anything the 300 will supersonic(and then some no 125 grain 300 will run 2400 fps) and also offer cheap plinking ammo

I'm just going to copy/paste something I wrote in the post above.  It pretty much says exactly what you are telling me.



"If it was me, and I wanted a 7.62x39 AR-15 to shoot up a lot of cheap plinking ammo."
 

The ONLY advantage to 300BO is if you reload/SBR/pistol/supressed. If you do not fall into any of those category... go 7.62x39.
With a 16 or so barrel, you gain NOTHING with a 300BO (it was designed for 8.5", and a longer barrel nets you nothing).
X39 is FAR cheaper to obtain (even considering the mags/bolt/barrel) than 300BO and has similar ballistics from a 16" barrel.
IMHO, you're a fool if you're running a longer than 8.5" 300BO, as your wasting your money (since x39 is WAY cheaper and same ballistics).
Less than 10" = 300BO
Longer than 14.5" = 7.62x39.
People need to remember that 300BO was designed for a 8.5" barrel SURPRESSED. 300BO ammo is expensive, not common/easy to find, and does not offer an advantage for "civilian legal" rifle barrel length.
Can you tell that I'm not a fan of 300BO? haha
Go x39.
It's really that simple.

The 300 blk has a slight edge over x39 at longer ranges.
300 blk uses the same standard parts as the 556. x39 needs bolt modification to work and still pushes the limits of the AR15 design to fit the case in the upper.
300 blk uses the same magazines as 5.56. 7.62 does not.
The only, ONLY advantage to 7.62x39 over 300 blk is the cost of ammo and the cheap ammo you will find is all steel cased. when you compare brass cased quality ammo the different is marginal.
Just because a round was designed to function with a shorter barrel does not mean it cannot function just fine in a 16" barrel. it does so and does so while giving you multiple advantaged over the 7.62x39 while offering similar or better performance.

And, like all .300 BLK haters, you don't mention its subsonic advantage.  And you continue to push the false narrative about the cartridge being designed for a suppressed SBR.  It was designed to be able to run supersonic and subsonic rounds effectively from the same platform.



The ignorant sentence I highlighted in red in your post above is really all that needs to be pointed out in order to completely discredit your opinion on the matter.



Nothing personal, but in a tech forum you should know what you're talking about before you chime in.



 

Top upper is 7.62x39:




I worked with Liberty Gun Works to build an upper I specced. It has been flawless through 2500 rounds. Mine uses a Black Rifle Arms midlength barrel, and Liberty's enhanced bolt. I've run the CPD 28rd magazines, exclusively, and like I said, the function has been flawless. Running Wolf ammo.

You should definitely do it.  It's super fun, a bit of a pain in the ass but if you get a Cason Engineering or LMT bolt (plus a few other minor adjustments) you should be good to go.

Also, I don't think many people would recommend 7.62x39 for home defense.  5.56/.223 is much better.

Thanks for the help. I think I'll build one in 7.62x39 over the winter.

I hope it goes well, and you end up with a reliable gun.



 

I had Model1 do an upper for me a few years ago.  At first I thought I had issues with it.  The lower parts kit that came with it had a crappy trigger.  Recently built another Anderson  lower with a Strikeforce stock and DPMS parts kit to use with it.  It's sweet now.  Just yesterday I got out to sight it in with a new Vortex Diamondback HP.  Suppressed at 100 yards with Wolf 123gr FMJ.  I think there were actually three rounds that went through the larger hole.  The low right shot is my first round of Fusion 123gr.  It clearly had more pop than the Wolf.  

This is acceptable to me.

Yes!
Mine is a 12.5" pistol at the moment.
Surplus ammo and arms 16" cut and reprofiled
AIM x39 BCG
Enhanced firing
springco red
AAC single chamber brake
H2
ASC mags
10" ALG rail and VCAS sling

]

I built my son a 300BO and my wife a 7.62x39 AR a few months ago and wish I'd have just built two x39's to begin with now.  I built my son's because I picked up the barrel cheap and my wife's so I could shoot brass cased PPU to resize it to 6.5 Grendel. They are both used for hunting and after trigger time with both I just prefer the 7.62x39 to the BO. With no plans to ever suppress my sons I cannot see any advantage the BO has over 7.62x39 and brass cased ammo is about half price for x39. I know there is a better bullet selection for BO, but Hornady makes a SST for x39 so really I don't need to look any farther.


ETA.. This is the second x39 I've had. The first was a post ban DPMS that would only run with a 5rd Colt mag and the old frankenmags. This hasn't ever had a problem and we shoot it with 20rd Magpul mags loaded with 5rds. I did get the extra power hammer spring and longer firing pin, but haven't had to install them..

I can see no reason not to build a 7.62 x 39 . I had contemplated building one myself but I am a reloader and have several thousand pieces of 5.56 brass so the blackout made more sense for me . Im not going to debate or wave the my favorite caliber is this flag its not what the op asked about .  I researched the x 39 hard and ask alot of questions from users it all comes down to using quality parts and what you feed it . certainly its going to be hard to find plinking ammo for a centerfire rifle any cheaper than 7.62 x 39 and if your looking for home defense ammo buy some of the hornady z-max its nothing more than a v-max bullet with a green tip and should expand and fracture great at hd ranges . take a chance if you dont like it all you have to do is get a new bolt and barrel to swap calibers.

Yes, I love mine.
I use the D&H tactical magazine and wolff extra power hammer spring and haven't had any issues.

I DID mention subsonic (suppressed). Perhaps you can't read? And YES, the 300 was designed for an 8.5" barrel suppressed (to keep it reasonable length with suppressor attached), as I've said. And NO, the 300 BO has no advantage over the x39 from a 16+" barrel. Do your research.
I'm not a 300BO hater, I just know the facts/ballistics and know that unless you are running a VERY short barrel, or suppressed, there is no advantage. Sorry to burst your 300 bubble.
Perhaps you should research more before YOU chime in next time. If you care to link why the 300 excels from a 16" barrel... please do so.
ETA: https://en.wikipedia.org/wiki/300_AAC_Blackout_(7.62%C3%9735mm)
BTW, I'm not your average JOE. I could reload 300 for similar cost to x39, but that wouldn't account for my time/labor. You can buy combloc x39 for the same and saver yourself the time/labor.
That being said... if ever a time came when import x39 was no longer available... the situation may change.

What magazines are you folks using? I grew up shooting an old Colt 7.62x39 and all of the mags except for frankinstein mags sucked. I see some photos of modern mags in this thread, I'm curious what you are using and if they are reliable.



Personally, unless something has changed in the magazine scene, I'd get a 300 blackout or an AR lower that takes AKM mags.

CPd mags all the way the ones I got have never had a failure no need to modify anything they just work.

Not true the x39 will run brass case soft point ammo (PRVI) at 2400 fps out of a 16 inch barrel.  No 300 load can touch that. Golden tiger is close to that at 2375 with a bullet that has a pretty high bc.  The x39 will also push a 150 grain bullet to 2100 or 2200 fps about 300 fps faster than the blackout

I LOVE my x39. It has been 100% reliable over 5-700 rounds now. 100%!!!

I had an issue right off the bat with too small a gas port on an older model used barrel, drilled gas out a touch and it has run like magic since.

Everyone who shoots my guns tells me this is their favorite. It's accurate, reliable, and that extra punch is so much fun.

I have used asc and c products mags. C products already have the front lip beveled down and load easier for some reason, but both work.

Faxon middy barrel with radical nitride bcg and off you goooo.

I've been looking at a bunch of 7.62x39 stuff. Does anyone make a 15 round magazine?

You said there was no advantage but the previous poster showed there were many advantages over trying to stuff a round made for the AK into the AR..

Such as a not needing a special bolt that has a tendency to break since a large portion and a decent amount of the metal needs to be milled out to accommodate the larger diameter of the casing.

Not needing special mags that fit into an AR magwell instead of an AK magwell that tend to be more expensive, less reliable and a heck of a lot less available than the standard GI magazines.

As mentioned above subsonics.

The 300BLK also has a lot more bullets to chose from as it shoots the .308 bullet that has hundreds of different varieties of cheap plinking, subsonic, tracer, hunting or home defense. The 300BLK also has bullets specifically made for hunting and home protection that any AK bullet would have a hard time even coming close to matching in terminal ballistics.

I did find it a little funny that you actually are trying to say that the 300BLK was mainly designed to work with a short barrel and use that as an advantage for you to put a 16 inch barrel for your AK mod is better yet the 7.62X39 was NEVER even meant to be put into an AR whether it is a 16 inch or 8.5 inch. The 300BLK was specifically designed to work flawlessly with no compromises in the bolt, no specialty mags or lowers and to work with all standard AR parts except for the barrel.

While the 7.62X39 is a formidable cartridge as it has been proven on the battle field being shot out of the simple rifle it was designed to work in. Trying to stuff it into gas operated rifle that was in no way shape or form designed for it just causes to many compromises that are hard to overcome.

It just seems pretty simple to me. If you want a cheap plinking rifle to shoot the 7.62X39 round just buy an AK as it will work every time you pull the trigger without having to worry about mag problems or breaking a bolt. If you want to shoot a .308 bullet out of the AR platform with more precision than an AK can give you the 300BLK can do it better with no compromises and with just a barrel change. I mean how does it make any sense to spend all this money on putting an AK AR together so that you can get more accuracy out of a round that was never meant for accuracy?

I like my AR in 7.62X39 better than any of my AK's.
Over 1400 rounds through 2 different 7.62X39 AR builds.
Compared to my AK's,
My AR's n 7.62X39 are More accurate, easier optic mounting, better controls, softer recoil, mags don't rock in, easy to change barrels and parts,
More expensive mags, can always switch to another caliber with diff barrel, bolt and mags, cheap ammo.
Just a few thoughts

No.

Because Sota arms has complete 7.62x39 uppers for $280. For a range toy would be hard to beat

OK, you did mention SBR/Suppressed.  My bad.



But the fact is that the ONLY advantage 7.62x39 has over .300 BLK in a 16" barrel is bulk ammo cost.



Please cite where the .300 BLK was designed around an 8.5" barrel.  I'll eat more crow if you can do that.  Because what I know is that the cartridge was designed to maximize efficiency from supersonic rounds from a 16" barrel.  MV increases by over 300 fps, and ME by almost 30% from a 16" barrel relative to an 8.5" barrel.  So how can you say that "a longer barrel nets you nothing?"



The 300 AAC Blackout was designed to achieve energies similar to the 7.62x39 in an AR-15 platform while using standard AR magazines at their full capacity.  To achieve this goal you don't use an 8.5" barrel.



 

And at 300 yards the 7.62x39mm bullet has how much retained energy compared to, say, a 125gr. Barnes TTSX?

7.62×39mm	123 gr (8.0 g)	16.5 in (420 mm)	2,396 ft/s (730 m/s)	0.280	712 J (525 ft·lbf)
300 BLK	115 gr (7.5 g)	16 in (410 mm)	2,295 ft/s (700 m/s)	0.300	777 J (573 ft·lbf)
300 BLK	125 gr (8.1 g)	16 in (410 mm)	2,220 ft/s (680 m/s)	0.320	829 J (611 ft·lbf)

Look, the argument is pointless.  They are very comparable cartridges.  Do you want to shoot a lot of cheap ammo, or do you want a more versatile cartridge.  That's really all that matters.





 

Well said.



 

I got a 7.62x39 because I really had no desire to buy an AK, but I like the price and availability of the ammo.  I had a 20" DPMS upper, which I never could get to run right.  It always had nosedives in the mag.  My 14.5" Colt upper runs like gangbusters with the same mags.  

I also have a 7.8" .300, so keep the faith and get both!

I have DPMS frankenmags which seem to run the best in both the 20 and the 14.5.  I also have 6 heavily culled CP mags with Wolf heavy duty AK springs in them.

I don't really understand why everyone is blowing their load over the 300blk vs x39 argument. You can build an x39 upper for cheap and have lots of fun with cheap ammo. That's the whole point to it. Then it just so happens that after building mine not only has it been super reliable, but it has been astoundingly accurate, so much so that I'm gonna change scopes on the rifle so I can do up some 500 yard range action.

Sure, steel case 556 is as cheap as x39 now. Sure, 300blk has more bullet options. Whatever. The x39 is cheap and versatile, and there are good loads available for it (Hornady) and cheap hunting ammo is also available. Not only that, but x39 ammo is much more available worldwide. Everyone who says "well you should just buy an AK" has obviously never shot one of these x39 ARs.

Yes! Built 4 in the last few months. Lots of fun but takes some tinkering to get them just right.

The only problem I have had with my 7.62X39 AR is finding mags to run with it.

I have a few older ones that work well, and ordered new ones from the same MFG a couple years ago I could not get them to run even after modification.  I sent them all back to the supplier who said at the time everyone was having issues with this new batch.  My buddies bought some and said they finally broke in and worked after a few hundred rounds.

Having said that, I haven't ran it, or tired to find additional mags since end of 2013.  Did Magpul ever come out with a Mag for this set up?

I currently have 2 7.62x39 ARs and 2 300 Blackouts  I love all 4 and if I am running supressed Hands Down the 300 takes it. Otherwise for a light Mid range 30 cal I go to
the x39 every time . Both of mine run the Yankee HIll  Components and thr ASC mags without a HItch

I ran the 7.62x39 suppressed (.40cal can) and was actually quite surprised with the results. It wasn't much louder than 5.56