7.62x39 upper in 20"? - Page 3
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Old 12-04-2012, 08:01 PM   #21
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After looking into the Blackout, I think I'm gonna have to go that route. Although, it'd be nice to have an AK round as well, since they're so popular worldwide, I might have to go that route later on. First up for me, Blackout.

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Old 12-04-2012, 08:11 PM   #22
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Quote:
Originally Posted by CpnT0rch
After looking into the Blackout, I think I'm gonna have to go that route. Although, it'd be nice to have an AK round as well, since they're so popular worldwide, I might have to go that route later on. First up for me, Blackout.
Speaking of that... I know that you can use the same bcg, upper, and mags, but are there any suggestions on upgrading the firing pin like what was suggested for steel cased 7.62? Is it necessary for the .300 BO?
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Old 12-05-2012, 11:20 AM   #23
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No need to change the firing pin.

That is recommended for 7.62 due to hard military primers. 300 BO uses small rifle primers that are not as hard as the Russian military ones.

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Old 05-02-2013, 02:52 AM   #24
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Originally Posted by SSGN_Doc View Post
I'm not sure about a 20" barrel, but a standard upper works. Different bolt and mags are what you need. The mag is the weak link on a 7.62x39 AR. The round really needs a curved mag to feed well. The AR mag well is straight at the top and most folks experience feed problems. RRA introduced a different lower that uses actual AK type mags to alleviate this problem, but then that lower doesn't work with all the other calibers a standard AR would have as options because it won't take any if the AR mags.

Not to burst your bubble or discourage you, just letting you know that there may be some frustration ahead of you in this build.
AAARRRRGGGGHHHHH! NOOOO NOT TRUE! whoever started this myth should be SHOT! There is NO SUCH thing as a round designed for a curved magazine! AND the 7.62x39 was designed for use in the SKS which does NOT have a curved magazine it has a fixed ten round stacked box magazine. the socalled "banana clip" was designed for HUMAN convenience ONLY. there are other caliber rounds that have a greater taper than the 7.62x39 that are fed out of straight magazines, like oh say, the 5.56x45, you just don't notice it due to the length vs angle...
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Old 05-02-2013, 02:54 AM   #25
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Ive built HUNDREDS of 7.62 x 39 ARs for clients without a single issue because I supply the correct magazine not an adapted one and teach them about dirty ammo and it's consequences... Education is a wonderful thing.

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Old 05-02-2013, 03:29 AM   #26
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When you get a chance stop by the introductions thread and say hello.
Welcome to FTF.

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Old 05-02-2013, 05:12 AM   #27
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Ive built HUNDREDS of 7.62 x 39 ARs for clients without a single issue because I supply the correct magazine not an adapted one and teach them about dirty ammo and it's consequences... Education is a wonderful thing.
Ok. It doesn't need a curved mag. If you keep it short.

What mags do you provide for an AR mag well that work 100 % for the 7.62x39 round. I've only been around about a half dozen ARs in 7.62x39. And with any high cap mag they would tend to fail to feed, because rounds would bind near the transition from the curved portion of the mag to the straightened portion that fit inside the mag well. Problem seem common enough that Rock River made a different lower to use AK mags to get a reliable high cap mag for the AR in this chambering.

I will say that with a 5 round hunting mag I have seen 7.62x39 ARs work fine. So if folks don't want a high cap for their AR then they are probably fine. If someone makes a reliable high cap mag in the chambering for these rifles I'd love to let a couple of my friends know who makes them.

As to the dirty ammo. Yeah, it might cause some issues, but even the .223/5.56 Wolf and Russian manufactured ammo is just as dirty, and I've seen ARs run a steady diet without cleaning for over a thousand rounds without cleaning, and still running fine, ( dirty but fine).

The real problem may lie somewhere in the middle. Just know what I've seen with the 5 or 6 7.62x39 ARs I've seen.

Here is a dirty AR that was still running.
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Old 05-02-2013, 10:06 PM   #28
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Quote:
Originally Posted by Nectoxicdragon View Post
AAARRRRGGGGHHHHH! NOOOO NOT TRUE! whoever started this myth should be SHOT! There is NO SUCH thing as a round designed for a curved magazine! AND the 7.62x39 was designed for use in the SKS which does NOT have a curved magazine it has a fixed ten round stacked box magazine. the socalled "banana clip" was designed for HUMAN convenience ONLY. there are other caliber rounds that have a greater taper than the 7.62x39 that are fed out of straight magazines, like oh say, the 5.56x45, you just don't notice it due to the length vs angle...
5.56x45 is more tapered than 7.62x39? Since when?

Even so, the last time I looked 30rd AR mags curve below the magwell though not as much as AK mags. If you line up 30 AK or AR rounds they curve quite a bit which is no doubt the reason the mags are shaped the way they are. "Human convenience", when was that taken into consideration when desigining the AK? (I love it but ergonomic it ain't!)
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Old 05-02-2013, 10:19 PM   #29
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Oberland arms makes ar10s up to 26" barrels. They are German, but are found in the states. Might want to check Schmeisser too, because they make twenty inch barrels. HK makes 16" barrels. Hera arms also makes 20" barrels, but I think for only .223. Sig only makes 16" ARs, but for .223. That is it for German AR10s.

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Old 05-02-2013, 11:02 PM   #30
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Quote:
Originally Posted by Quentin View Post
5.56x45 is more tapered than 7.62x39? Since when?

Even so, the last time I looked 30rd AR mags curve below the magwell though not as much as AK mags. If you line up 30 AK or AR rounds they curve quite a bit which is no doubt the reason the mags are shaped the way they are. "Human convenience", when was that taken into consideration when desigining the AK? (I love it but ergonomic it ain't!)


Also I don't think anyone said the round was designed to have a curved mag. Pretty sure no one said I want to design a round that is going to require a curved mag. The round was developed they way it was developed. The need for a curved mag just followed the needs required by the round. Smooth feeding through the full length of the body of the mag is going to enhance reliability, by reducing binding, and keeping even upward pressure on rounds as they feed.
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