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Posted: 8/22/2017 9:56:30 AM EST
Well I've been toying with the idea of taking my one AR that's been through every imaginable change possible and making it into a 7.62x39 AR.

It started life as a regular 16" heavy barrel DPMS that I had purchased while in Afghanistan. This was also around the same time as Sandy Hook, so I paid way way way more than I should have but being overseas and with limited internet access, I bought first one I could fine.

I've rebuilt this DPMS in several different configurations, always in 5.56. However, I got to looking last night and been thinking I want to build it into a 7.62x39

The rifle as it sits now is painted, so his will mainly a hunting rifle but will be also for fun. I know I need to get a new barrel, bolt carrier group, and magazines.

I've already got a ALG defense trigger installed, and the rail I'm running is an ALG defense rail as well.

Anything specific I need to make sure I do so I can build a reliable rifle?
Link Posted: 8/22/2017 10:06:31 AM EST
[Last Edit: 8/22/2017 10:19:32 AM EST by V-Rod]
Radical Arms from Texas builds a decent one, AIM was selling them for 450 shipped once upon a time. I believe they were selling barrels and bolt assy as well. Its a fun caliber to shoot cheap and the bolt hold open after last round

https://www.aimsurplus.com/catalog.aspx?groupid=6504&name=7.62X39+AR+Accessories
eta link added
Link Posted: 8/22/2017 10:08:06 AM EST
You need to get parts.
Link Posted: 8/22/2017 10:16:43 AM EST
First you need a 7.62x39 upper. That's the easy part, and there are a few different choices out there.

Next you will need magazines. When Colt first started selling 7.62x39 ARs, they just provided them with a 20rd straight GI 5.56 mag, and told you not too load too many into it. If you load too many, the steeper taper of the M43 case causes the top rounds to start to nose under and it won't feed reliably. This solution works fine if you don't mind having 12-13rd magazine capacity.

You may also need to replace your hammer spring with something heavier to fire the notoriously-hard primers of milsurp 7.62x39 ammo. If you are buying American-made, commercial brass-cased 7.62x39, or reloading your own with standard primers, that step may not be necessary.

There are probably some US-made 7.62x39 magazines made these days that will work better than the old Colt solution.

If you're willing to use a different lower, then the "AR-47" type lowers have a different magazine well which accepts standard combloc 7.62x39 magazines, and that nicely addresses any magazine and feeding issues, at least.
Link Posted: 8/22/2017 11:26:57 AM EST
I forgot to mention in my first post that I'm looking to use the radical arms 16" midlength barrel and an AIM BCG.

For magazines I'm looking to use the C product magazine.
Link Posted: 8/22/2017 12:26:40 PM EST
built up 3, all i did was take .010 off the firing pin and they all work, CP mags are the way to go.
Link Posted: 8/22/2017 1:39:52 PM EST
I ordered a complete upper from PSA PA47 16" 7.62x39 upper w/BCG and Charging Handle, and CPD mags, and have 800 flawless round through it shooting cheap steel ammo. I beleive the barrel, BCG, and mags, are the only difference.
Link Posted: 8/22/2017 2:07:13 PM EST
Bolt, Barrel, Mags.
Link Posted: 8/22/2017 3:14:03 PM EST
[Last Edit: 8/22/2017 10:10:47 PM EST by mouthpiece]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Desert_AIP:
Bolt, Barrel, Mags.
View Quote
CPD GEN III MAGS
That and a RedXArms extended firing pin for $10 or $11 shipped.
Also, use standard strength hammer springs or a Geisselle trigger group.
All of the cassette type Trig groups that I tried(POF, BRO, Timney AR10...)will not fire hard primers of steel case ammo about 30% of the time.
Link Posted: 8/22/2017 7:16:03 PM EST
the AIM BCG's for 7.62x39 come with the right firing pin, no separate purchase necessary. speaking from experience.

with your ALG trigger, and CPD mags, barrel, you should be all set. if it's a carbine M4 config, with the std M4 buffer spring, you might need to step up to a H3 buffer. to be determined when you function test with live ammo for last-round bolt-hold-open.
Link Posted: 8/22/2017 7:57:05 PM EST
[Last Edit: 8/24/2017 7:37:31 PM EST by crazysarge16]
Looking around tonight, the build (once complete), will be assembled with the following parts:

Stuff I have
-DPMS lower/upper off original DPMS ride
-Milspec buffer tube
-BCM Mod 1 stock
-Spikes T2 buffer with silicon spring
-Tango Down grip
-ALG trigger
-ALG V2 rail
-Troy front /rear sight set

Stuff need to buy
-Faxon barrel This one
-AIM BCG This one
-C product magazines
Link Posted: 8/22/2017 8:01:57 PM EST
[Last Edit: 8/23/2017 10:32:09 AM EST by Aimless]
[Deleted]
Link Posted: 8/22/2017 10:17:35 PM EST
My Green Mountain 1:9.5 twist 16" barrel is a tack driver. I opted for a RCA BCG and do my own trigger work.
Link Posted: 8/23/2017 9:24:37 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By crazysarge16:
Looking around tonight, the build (once complete), will be assembled with the following parts:

<Snip>

Stuff need to buy
-C product magazines
View Quote
CPD or C Products Defense is what you want, not the standard C-products. northriverllc.com, aimsurplus.com, and a few other places carry them.

Are you reusing your gas block and gas tube? If not, you'll need those too. Oh, and ammo, possibly a new bore snake or chamber brush to clean with.
Link Posted: 8/23/2017 9:34:48 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By tlbailey1:


CPD or C Products Defense is what you want, not the standard C-products. northriverllc.com, aimsurplus.com, and a few other places carry them.

Are you reusing your gas block and gas tube? If not, you'll need those too. Oh, and ammo, possibly a new bore snake or chamber brush to clean with.
View Quote
On the barrel currently installed is a shaved down A2 front sight. Probably have less than 500 rounds through it as set up so I'll just pass it on to someone on the EE.

The radical arms barrel I'm looking at getting had the pinned gas block. Also it's a midlength so I'll just resuse the same Spike's Tactical melonite midlength gas tube that's currently installed.

I believe I've got a new brush somewhere, but that's not a huge concern. Easy to obtain.

More I read about what people have done to make them reliable the more I want to do it. Have built x2 300 AAC Blackout, enjoyed the round and only had one FTF issue with a certain type ammo. Just can't afford to buy as much bulk 300 as I can of 7.62x39.

Plus, don't reload currently and have a kid on the way so funds are tight
Link Posted: 8/23/2017 10:58:34 AM EST
Link Posted: 8/24/2017 6:57:31 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By joshv06:
Here's a video I made last month on this topic:

https://www.youtube.com/watch?v=-HELihkBV0Y
View Quote
Thanks, did I hear you correctly in video that you used the Radical midlength barrel?

Nice looking build
Link Posted: 8/24/2017 10:59:39 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By crazysarge16:
Thanks, did I hear you correctly in video that you used the Radical midlength barrel?

Nice looking build
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By crazysarge16:
Originally Posted By joshv06:
Here's a video I made last month on this topic:

https://www.youtube.com/watch?v=-HELihkBV0Y
Thanks, did I hear you correctly in video that you used the Radical midlength barrel?

Nice looking build
He clearly used Faxon and stated that they had their MLGS worked out well with that cartridge.

I watched the whole thing and heard no mention of Radical.

If you do a search, Radical has had problems with barrels and barrel extensions untorquing under fire, especially in 7.62x39.

When Colt spent who knows how much money doing the RDT&E on 7.62x39 in the 1980s, they did many things that I never see being addressed in the current after-market, who seem to be totally ignorant of Colt's work on that project.
Link Posted: 8/24/2017 7:39:09 PM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By LRRPF52:
He clearly used Faxon and stated that they had their MLGS worked out well with that cartridge.

I watched the whole thing and heard no mention of Radical.

If you do a search, Radical has had problems with barrels and barrel extensions untorquing under fire, especially in 7.62x39.

When Colt spent who knows how much money doing the RDT&E on 7.62x39 in the 1980s, they did many things that I never see being addressed in the current after-market, who seem to be totally ignorant of Colt's work on that project.
View Quote
You are completely correct. I don't know why I had Radical stuck in my head. Heck, even the barrel I'm talking about using and put the link too is the Faxon barrel
Link Posted: 9/13/2017 12:39:18 AM EST
Where can one find a "Heavy / Extra Power" Hammer Spring?

I've looked under Palmetto State Armory & Primary Arms with no success.
Link Posted: 9/13/2017 3:16:21 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Bigger_Hammer:
Where can one find a "Heavy / Extra Power" Hammer Spring?

I've looked under Palmetto State Armory & Primary Arms with no success.
View Quote
Brownells be my first place to look, if not Midway.
Link Posted: 9/13/2017 3:28:43 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Bigger_Hammer:
Where can one find a "Heavy / Extra Power" Hammer Spring?

I've looked under Palmetto State Armory & Primary Arms with no success.
View Quote
Wolff springs

https://www.gunsprings.com/

Dealers everywhere have them also....

Id stay away if it isn't a Wolff...imho.
Link Posted: 9/15/2017 8:25:56 PM EST
Who makes a good reliable bcg for a 7.62x39 AR?
Link Posted: 9/15/2017 8:33:09 PM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Christopher67:
Who makes a good reliable bcg for a 7.62x39 AR?
View Quote
Toolcraft
Link Posted: 9/15/2017 9:09:41 PM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Christopher67:
Who makes a good reliable bcg for a 7.62x39 AR?
View Quote
Rubber city Armory
Link Posted: 9/15/2017 9:13:52 PM EST
Link Posted: 9/16/2017 6:57:02 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Christopher67:
Who makes a good reliable bcg for a 7.62x39 AR?
View Quote
AIM Surplus
Link Posted: 9/18/2017 3:24:21 AM EST
http://palmettostatearmory.com/psa-pa47-16-carbine-length-7-62x39-nitride-upper-without-bcg-or-charging-handle-5164463801.html
Complete upper minus bcg for $150 shipped!

I have only used aim BCGs. Never needed to change the hammer spring or firing pin.
Link Posted: 9/18/2017 8:43:42 AM EST
Link Posted: 9/22/2017 11:00:59 AM EST
Does anyone have one of these bolts?

AR15 7.62x39 Bolt Option#1

AR15 7.62x39 Bolt Option#2
Link Posted: 9/24/2017 5:16:49 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Christopher67:
Does anyone have one of these bolts?

AR15 7.62x39 Bolt Option#1

AR15 7.62x39 Bolt Option#2
View Quote
I have the LMT bolt in a pistol 7.62X39 with 1000 rounds on it.
So far all is good
Link Posted: 9/24/2017 7:01:50 AM EST
I just purchased a PSA Ar in 7.62-39 and a Bear Creek upper in same caliber. I have not shot them yet will I need enhanced firing pin? I see Red X Arms has some. Any other issues others have had with same guns/uppers?
Thank all!
Huck
Link Posted: 9/24/2017 7:08:23 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Huckleberry689:
I just purchased a PSA Ar in 7.62-39 and a Bear Creek upper in same caliber. I have not shot them yet will I need enhanced firing pin? I see Red X Arms has some. Any other issues others have had with same guns/uppers?
Thank all!
Huck
View Quote
With some ammo you might need a Wolff +15% hammer spring. I didnt need anything else, firing pin should be ok. I have the PSA.

SGAmmo had some 223 ammo that was manufactured with wrong primers they sold at a great discount you needed an extended firing pin for.
Link Posted: 9/24/2017 7:39:52 AM EST
I have not seen it mentioned that you will need a muzzle device. Not sure if the Faxon comes with one. I bought a complete upper from Sanders armory and it has ran flawlessly after I installed an enhanced firing pin from Red X. I also am running the C P Defense mags as opposed to the older C products mags. I recently got 2 ASC mags and they worked for the few rounds I put through them. They look identical except they are "parkerized" and the C P Defense mags are a slick black finish.
Link Posted: 9/25/2017 1:30:01 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By mouthpiece:


I have the LMT bolt in a pistol 7.62X39 with 1000 rounds on it.
So far all is good
View Quote
Thanks!
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