Who Here Has Built A 7.62 x 39

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[ARCHIVED THREAD] - Who Here Has Built A 7.62 x 39

Posted: 8/31/2014 3:20:41 PM EDT

Howdy All
I'm wanting to build a 7.62 x 39 AR. I have a few questions and if the question sounds dumb it's because I don't know the answer and need to ask .

Can you use a mid length free float tube with a carbine length gas system? I was looking to buy the 16 inch barrel from Brownell's and it says that it has a carbine length gas system.

Are M4 feed ramps standard on a Rock River upper receiver and will they match the barrel extension on the Brownell's barrel? Brownell's did not say what feed ramps were on the barrel extension. Do you order the barrel extension separately to match the receiver ?

Those of you who have built a 7.62 x 39 what issues / problems did you encounter? Who did you order your parts from?

The lower receiver I am going to use is a Aero receiver with a Rock River two stage trigger parts kit. I've put together two lowers but haven't built an upper before. Thanks

Posted: 8/31/2014 6:39:06 PM EDT

[#1]

I run an AP Carbon rifle length tube on a Carbine gas if that helps you any. There is a 7.62x 39 thread on the pistol forum that might be helpful.

Posted: 8/31/2014 7:03:04 PM EDT

[#2]

I had to get a Wolf extra power hammer spring so the rifle would reliably ignite Russian ammo with the hard primers
also turned the end of the firing pin down so that it would stick out further.

I think that the RRA 2 stage would not be as nice of a trigger if I put it in with an extra power hammer spring

Posted: 8/31/2014 9:17:12 PM EDT

[#3]

I built mine mid-length, it runs fine. I'm not having any ammo or primer issues, it's shot everything I've tried. I bought the barrel/ bolt as a package deal from either Brownells or Midway. I'll have to look to be sure and for the price. It was a fair price for a stainless barrel with the 7.62x39 bolt or I would have passed. My son bought the same combo, it has been problem free as well.

Posted: 8/31/2014 11:53:09 PM EDT

[#4]

You have no issue using any free float handguard length with a carbine gas system and low profile gas block. I was just checking bolt carrier groups earlier this evening for the 7.62x39 I've started and I'm pretty settled on getting one from Tactical Ambush. Sota Arms has one at a really good price also though.

I'm still planning on a pistol build though so I'll be using a 7" free float hand guard if it's going to end up being a pistol. I won't know for sure if I'm going pistol or carbine until the end of the week though. I might get some free parts that would mean I'll make a carbine.

Posted: 9/1/2014 12:02:06 AM EDT

[#5]

Carbine gas with a low profile gas block will work fine under a mid length rail. Receiver extension will be mounted to the barrel. At this point all new production 7.62x39 barrels will have M4 ramps and you will want an M4 ramped upper receiver to go with it. Brand of upper receiver shouldn't make any difference.

RedX arms has an extended firing pin for the 7.62x39, it is .010 longer for more reliable ignition on combloc ammunition. Many people use extra power hammer springs to help make sure the hard primers ignite.

Posted: 9/1/2014 1:05:16 AM EDT

[#6]

Thank you all for your help. So I can use any length free float tube, that sounds good to me. I will be using a low profile gas block. Is the bolt carrier the same as you would use for a 5.56 just a different bolt for the 7.62 x 39. cartridge? What kind of accuracy have you got with your rifle?
I was thinking of buying a complete upper but would like to do it myself.

I Didn't know that a .010 longer firing pin was available for this build, good info in case I need one

Posted: 9/1/2014 8:34:14 AM EDT

[#7]

Yes, the carrier is the same...

Posted: 9/1/2014 11:20:34 AM EDT

[#8]

Horseman I'll check out the thread on the pistol forum and Paul thanks for the info on the bolt carrier I thought they would be the same but wanted to make sure before placing an order. MC

Posted: 9/1/2014 12:11:08 PM EDT

[#9]

Yep, the bolt carrier is the same, it's the bolt that's different. I'd get one of the complete BCG's from a company though anyway. The Tactical Ambush one is currently $109 and is advertised for being strengthened specifically for being able to reliably use the eastern bloc cheap steel cased ammo. I'm sure I'll be shooting enough of that when I have mine finished so that's sounding good to me. Other's here may have some really good recommendations also which I'll be happy to hear.

Posted: 9/1/2014 1:42:09 PM EDT

[#10]

SMITHIV thanks for the heads up on the complete bolt carrier group for the 7.62 x 39. The barrel that I was looking at Brownell's comes with a bolt. I guess I could always sell the extra bolt or just keep it.
Anyone have any suggestions as to where to buy a barrel from and or what barrel is a good one for my build. I'm not looking to pinch pennies just want a good quality accurate barrel.

Posted: 9/1/2014 2:15:35 PM EDT

[#11]

Would suggest a chrome lined or melonited barrel.

Posted: 9/1/2014 7:06:58 PM EDT

[#12]

LastRites any suggestions on who sells those barrels? MC

Posted: 9/1/2014 7:39:17 PM EDT

[#13]

Quote History

Quoted:
SMITHIV thanks for the heads up on the complete bolt carrier group for the 7.62 x 39. The barrel that I was looking at Brownell's comes with a bolt. I guess I could always sell the extra bolt or just keep it.
Anyone have any suggestions as to where to buy a barrel from and or what barrel is a good one for my build. I'm not looking to pinch pennies just want a good quality accurate barrel.

View Quote

There are a number of places you can check for barrels and you should be able to get a melonite barrel for under $200. I just did some checking from a lot of the websites for manufacturers though that I check for available barrels and the only one I find with a melonite barrel in stock is MAS Defense. They have 16" melonite barrels listed as available at $159 which isn't a bad price. Mostly I've been looking for 7.62x39 pistol barrels. JSE Surplus lists a Yankee Hill Machine chrome lined barrel at just under $200 but, out of stock and others I checked also seem to be out of stock for melonite/nitride or chrome lined barrels. I find several steel heat treated or phosphate finished barrels available in carbine length. I haven't checked the really high end market manufacturers like Harris or KAK Industries though. They tend to be very high priced.

Posted: 9/1/2014 8:17:53 PM EDT

[#14]

Thank You SMITHIV I'll look around and see what I can find. MC

Posted: 9/2/2014 7:13:05 AM EDT

[#15]

I bought my barrel from Alpha Shooting Sports when it went on sale for ~$120.

http://www.shop.ar15hardware.com/category.sc?categoryId=39

It's been a lot of fun.

Posted: 9/2/2014 8:40:01 PM EDT

[#16]

I built mine using a bolt and barrel combo that I got from Mas Defense. About 500 rounds through without a single hiccup. Not only do I love this gun, but everyone that I let shoot it loves it too.
Quick pic for visuals

Posted: 9/2/2014 11:49:08 PM EDT

[#17]

Midas nice looking rifle what kind of groups are you getting at 100 yards?

Posted: 9/3/2014 2:04:09 AM EDT

[#18]

What magazines is everyone using?

Posted: 9/3/2014 4:59:36 AM EDT

[#19]

My older brother is going for an MGI build.

Uses AK mags.

He's going to the AR platform for:

QD Suppressor mount attachment concentricity
Freefloat barrel
Accuracy
Modularity
ease of Barrel change

Should be interesting.

Posted: 9/3/2014 9:05:32 AM EDT

[#20]

I'm building a 7.62x39 upper too, decided against the .300 blackout since ammo is so expensive and I have lots of 7.62x39 rifles and ammo. I'd like to find a good nitrided or chrome lined barrel. Most of the nitrided barrels out there are ARD barrels that most say are not truely melonited as you can scratch them very easily. I have owned ballistic advantage barrels and can attest to the durability and corrosion resistance of their nitrided barrels, wish they would start making 7.62 barrels again.

Posted: 9/3/2014 2:35:57 PM EDT

[#21]

Quote History

Quoted:

What magazines is everyone using?

View Quote

Anyone?

Posted: 9/3/2014 5:08:50 PM EDT

[#22]

C Products Mags

Check Green Mountain Barrels before you order. I got my 7.62x39 there for $159 a couple of months back.

Posted: 9/3/2014 10:45:09 PM EDT

[#23]

Quote History

Quoted:
I'm building a 7.62x39 upper too, decided against the .300 blackout since ammo is so expensive and I have lots of 7.62x39 rifles and ammo. I'd like to find a good nitrided or chrome lined barrel. Most of the nitrided barrels out there are ARD barrels that most say are not truely melonited as you can scratch them very easily. I have owned ballistic advantage barrels and can attest to the durability and corrosion resistance of their nitrided barrels, wish they would start making 7.62 barrels again.

View Quote

Black Rifle Arms sells the BA 7.62x39 barrels. Ares Defense also sells a Ntiride one. I have 3 but haven't used them yet. The ARD ones probably aren't melonite, but damn I will say they work very very well. TR Enabling also sells chrome lined ones.

To date I've put together between 15-20 7.62x39 Uppers. Most of them have used Mas Defense's phosphate barrels, but they are really nice as well in my opinion. Only barrels I have had issues with are Tactical Ambush (nitride as well). The gas port was way too small, and after trying to explain that issue, a barrel showed up one day with the hole redrilled. They haven't responded at all to me trying to find out if they want me to send one back or not. I haven't had a chance to use it yet, but I would say they righted a wrong and would give them another shot.

I have spent lots of money on finding what works because I believe in the round for the platform. I feel the days are over of people blaming the AR magwell or broken bolts or light strikes. I have had excellent results with new ASC and CPD mags, new bolts are made of 9310 instead of 8620 like older ones were, and enhanced firing pins are readily available as well as the ability to mod your own. I haven't shot enough rounds to know if the bolt will break, but as soon as I save up some more cabbage and get the range time, I will torture test one.

Oh and 7.62x39 ARs also make great pistols!

Posted: 9/4/2014 12:28:46 AM EDT

[#24]

Thanks for the heads up on the tr enabling chrome lined barrel, I picked it up for $159. Would have preferred a mid length gas system but we will see how she runs.

Posted: 9/4/2014 12:44:31 AM EDT

[#25]

No problem! I think you will be very happy with the carbine length. The kick is nominal depending on your muzzle device choice and a little more forgiving when it comes to under powere ammo.

Posted: 9/4/2014 2:13:44 PM EDT

[#26]

What kind of accuracy are you folks getting with your 7.62 x 39 builds? Hand loads or commercial ammo. MC

Posted: 9/4/2014 11:44:40 PM EDT

[#27]

Pretty excited to see how an AR will shoot 7.62. We were out today shooting pepper poppers at 300 yards with my vz2008 and tula ammo. If you can hold the sights on the popper it would fall every time. The ammo is cheap and effective, the AR is much easier to put optics on, better triggers, free float ect... This rifle will be built with a light weight YHM free floating hand-guard taken off of my 5.45 build that I recently decommissioned due to running out of cheap 7n6 to shoot up. That 5.45 ran flawlessly for 1000's of rounds after a couple adjustments and the purchase of some c-products 5.45 magazines. Everyone talks about how unreliable 5.45 and 7.62 AR conversions are, I say that they just need to tweek them and use the correct magazines.

Posted: 9/5/2014 7:59:13 PM EDT

[#28]

What do you folks think about using a AERO Precision upper receiver with no forward assist on my build? MC

Posted: 9/5/2014 10:03:58 PM EDT

[#29]

Quote History

Quoted:
Pretty excited to see how an AR will shoot 7.62. We were out today shooting pepper poppers at 300 yards with my vz2008 and tula ammo. If you can hold the sights on the popper it would fall every time. The ammo is cheap and effective, the AR is much easier to put optics on, better triggers, free float ect... This rifle will be built with a light weight YHM free floating hand-guard taken off of my 5.45 build that I recently decommissioned due to running out of cheap 7n6 to shoot up. That 5.45 ran flawlessly for 1000's of rounds after a couple adjustments and the purchase of some c-products 5.45 magazines. Everyone talks about how unreliable 5.45 and 7.62 AR conversions are, I say that they just need to tweek them and use the correct magazines.

View Quote

Here are three 3 shot groups at 50 yds using my Eotech 553 after I zeroed it. At the Gamelands in PA rifles can't have more than 3 rounds loaded or the game commission will fine you if caught. Same barrel and BCG used on the ones I'm selling in the EE too (HINT HINT)

http://i716.photobucket.com/albums/ww164/ViperHummel/photo19-1.jpg

Posted: 9/5/2014 11:02:18 PM EDT

[#30]

Cowboy, I really dislike those uppers without fa's from a cosmetic standpoint, also it will be harder to sell later if you decide to. Viper, that's a good group hoping mine will shoot as well with my horde of tulammo.

Posted: 9/5/2014 11:12:03 PM EDT

[#31]

I bet it will. The Tula did pretty decent too. That's what I used to group and zero and then ran out so I switched to Red Army,

As far as the no FA, think "dirty" Steel ammo, 7.62x39, and gas operated. If you want to depend on it, you might need to tap the FA. Plus, I feel most companies over charge for no FA but does have an ejection port cover. Anderson has one that has no FA or ejection port cover I and did do that for my 5.56 LW build. Great quality upper, but not that much in weight savings.

Posted: 9/5/2014 11:22:16 PM EDT

[#32]

Thanks for the reply Viper. I was thinking along the same lines too about dirty ammo. I've never used it on my 5.56 or .308 but like they say better to have it and not need it. MC

Posted: 9/6/2014 1:25:30 PM EDT

[#33]

I have built 4, 7.62x39 so far. I have had the best acuracy with YHM barrels with the 1in 9.5 twist instead of the more common1 in 10. Windhamhas announced theyare using the in their new AR in 7.62 x39. With the cheap Walmart ammo 1. 5 to 2 inches at 100 is often the result.

[ARCHIVED THREAD] - Who Here Has Built A 7.62 x 39

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