View Full Version : Taking the 7.62 x 39mm plunge
Finished my latest build which is a 7.62x39 mm SBR build. This build has been in the works for a long while. I used a JBO Spartan upper and lower along with a Seekins SLR rail. Stock is BCM. The barrel and bolt are from Radical Firearms. Now I need to get to the range and see how it runs.http://uploads.tapatalk-cdn.com/20160805/7690eb41078554a7b07b043ec68448b7.jpghttp://uploads.tapatalk-cdn.com/20160805/b9571a18140691ca0131cc36ce7eea23.jpg
Anyone come up with a lasting bolt yet?
Anyone come up with a lasting bolt yet?
Was just going to ask the same question. Is bolt life still around 1000 rounds? If so, that adds $100 to the price of each case of ammo. Ouch.
I'd be okay with 5k and no less.
Schmalkald
08-05-16, 17:09
Why???
When God created the perfect rifle for the 7.62 x 39 cartridge through his servant Kalishnikov?
Why???
When God created the perfect rifle for the 7.62 x 39 cartridge through his servant Kalishnikov?
This.
Why???
When God created the perfect rifle for the 7.62 x 39 cartridge through his servant Kalishnikov?
Why does a man do anything? Because he can. I wanted the ability to shoot low cost 7.62x39 mm without dragging the M92 SBR to the range. I don't always train on multiple rifle platforms.
Ergos, lrbho, accuracy, optics mounting, weight, custom build, etc. If there were reliable bolts I'd never buy another AK. Surely there has to be a means for making a custom bolt/barrel to make the system last.
I have 2 rifles chambered in this platform, each with about 2500 rounds and counting... no problems with either bolt !
Well since we aren't operating on a restricted server here like Hillary, please share the components so those that think they need a 7,62x39 Ar styled weapon can get the info.
I have 2 rifles chambered in this platform, each with about 2500 rounds and counting... no problems with either bolt !
I have 2 rifles chambered in this platform, each with about 2500 rounds and counting... no problems with either bolt !
What spring and buffer? I have one and can't get through a full mag w/o issues
KeithTexas
08-06-16, 22:58
What spring and buffer? I have one and can't get through a full mag w/o issues
I just completed my 4th build in this caliber. First three are PSA AR47 uppers and multi caliber blem lowers. I use ASC (20 round) and CProducts Defense (28 round) mags and they both run great. All have standard buffer springs, but I think I put an H2 and an H3 heavy buffer in a two of the rifles.
I've had no problem with bolts either, although I haven't run a ton of ammo through them yet. I have bought a few spares as I see them come up for sale every now and then (Black Rifle Arms has a nice melonited and MPI one I think I paid $60 for). AimSurplus too. Windham too on a budget. https://www.windhamweaponry.com/shopexd.asp?id=545
Regarding the 'upgraded' bolt - Liberty Gun Works in Florida make one he says is much stronger than standard. I think LMT used to. Also AR15 Performance will make you an 'extra strength/super alloy' one but I think they're about $90, can't remember. Extra strength bolt makers would would argue that how the bolt is heat treated is as important as the type of steel.
One is running a PSA and the other is an Underground Tactical bolt. As for spring just a standard carbine and got the SBR on a H2 and the carbine on a H1... I only use ASC 20 & 30 round mags without any issues !
Caduceus what mags are you using ??
What spring and buffer? I have one and can't get through a full mag w/o issues
I have tested my 7.62 PSA 16 inch carbine upper on a lower with collapsible m4 type stock with standard carbine, H and H2 buffers with the standard carbine spring, and I currently have it on an A2 lower with stock buffer and spring setup and no problems with any of these setups.
Was just going to ask the same question. Is bolt life still around 1000 rounds? If so, that adds $100 to the price of each case of ammo. Ouch.
The bolt on my 16 inch PSA 7.62x39 carbine gas upper is still together after 1,500 rounds. However, I did have to replace the gas rings at about the 1,000 round mark. I now have an additional 500 rounds on it since replacing the rings. Bolt seems to be doing fine other than that.
I don't know if they were just cheap rings or if it was something I could have done reassembling the bolt carrier group. The bolt was kept well lubed. The ends of the middle ring were very worn at the gap and the ring closest to the bolt head was worn to the point where part of the ring came out and was preventing the bolt from moving freely in the bolt carrier. I have a 5.56 carbine with well over 5,000 rounds on it, still with original gas rings.
I run a budget carbine that I put together from Anderson parts. I used a H2 buffer and put in an enhanced firing pin from RedXArms. I use ASC 30 and 10 round mags and haven't had any issues. The gun is surpisingly accurate for such a cheap barrel. I only have 800ish through it now. Hopefully the bolt will hold up.
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CMMG Mutant. Has a heavy bolt.
Why not just SBR an AK Pistol?
The AR platform is so good that seamlessly adding another caliber is a big deal. I bought an AR-Stoner upper assembly from Midway, stuck it on a stock Anderson complete lower and headed to the range. Some older Wolf ammo was giving a fair number of FTF's so I ordered a Black Rifle Arms enhanced firing pin. Now the only thing that ever, sometimes, goes wrong is that the bolt fails to lock back.
carbine357
08-17-16, 10:14
10.5" bbl by yankee hill
lower anyone's who work. I use tactical machining in florida
any std a.r.upper
mgi or model 1 sales (shotgun news) life time gurantee. approaching 2000 rds in 3rd year
30 rd mags I buy a.s.c. load to 25. get them from a guy up in Ohio who shoots his a lot.
met him at knob creek
cheapest 7.62x39 aim sells
aim point zero's to 1-1/2" at 50 yds
can hit a man size steel plate all day long at 250
what's not to like
carbine 357
p.s. whats the other most favorite ammo in the world
2 uppers same mainframe
my first 7.62x39 AR-15 upper was with the Anderson Mfg 16" carbine barrel, works great. AIM bolt, H3 buffer, std M4 buffer spring.
i then bought another AM 16" barrel, sent it out to get it chopped to 14.5, pinned & welded brake, also works great (AIM bolt, also H3 bfr), lot more fun than the 16" version.
then, getting adventurous, got a Faxon 16" mid-gas barrel, installed an Adams Arms piston kit. gas port enlarged to 1/8" works fine with Spikes T1 3oz buffer, reliable (won't do last round bolt hold open with the T2). enlarged the gas port to 9/64", works fine with Spikes T2 buffer. now it's dissassembled, going to send it out to get it chopped to 14.5, etc.
got a KAK 18" "Value-Line" mid-gas barrel, works reliably with the H3 buffer, but i think it's overgassed, from looking at steel cartridge case marks, sounds, etc. waiting for a SLR adjustable gas block for fine-tuning. just from the initial outing (function test) with a red dot, i think this one's going to be pretty darn accurate.
also sent out a Faxon 16" mid-gas to get it chopped to 14.5, pinned, welded etc, but this one will be DI, not piston. waiting for that to come back.
i use both CPD and ASC mags, 10rd, 20rd & 30 rd, AIM bolts all-around, nitride, blk phosphate, and NiB. on the mags, i actually like the ASC mags better, just have to romance them a little on the side feed lips with a stone so they don't snag or score the steel cartridge case as the bolt pushes it forward. everybody else recommends the CPD's, they're fine too. like i said, i have both.
in retrospect, 7.62x39, i think for 16" barrel, 14.5" barrel, from what i've read, and my own limited experiences, the carbine gas length is better. mid-gas 7.62x39 on the shorter 14.5" barrel might be pushing the envelope too far, IMHO.
my experience in a nut shell. YMMV.
Radical 10.5 upper, aim x39 bcg w/ .223 extractor and long FP, H3 buffer w/ sprinco red, and c products gen2 28 round mags working for me!
Using bcm extractor spring w/ crane o ring currently
6 full mags w out issue. Time will tell!
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