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7.62x39mm in a AR platform question

amusicman2

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Hi all. So I purchased a complete upper in said caliber and come to find out it is a .308 barrel. Since probably most all of you have more experience in this matter, have any of you shot the surplus .310-.312 ammo in a 308 barrel? That was the main reason for getting it. I have made up some using 125gr Nosler ballistic tips but that defeats the purpose of less costly ammo. I’m guessing they’ll work but wear the barrel out sooner? Thanks for any experience knowledge.
 

Reno

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What brand?
 
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amusicman2

amusicman2

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BCA. I know a lot of non likers of them out there but the cost was a deciding factor for a 1st time, easy conversion. I’ll see how the receiver and bolt hold up.
The lower is a S&W M&P 15.
 
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I dunno about whatever custom rounds you're making and stuffing through them, but BCA makes a nice upper for the $$

Anyone that thinks they're a bad company likely hasn't ever tried one of their uppers or is in disbelief of how could such a cheap upper be any good...

Well they manufacture their own stuff unlike many companies that rebrand barrels and such and sell as their own at a marked up price.


I was pretty skeptical of my BCA upper at first but after shooting it...that fell away quickly. shoots decent groups and it runs 100% reliably with the cheapest russian ammo available to us. I can't complain at all about mine.
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As for the bullet: 312 is standard size for a 7.62x39 round. 308 barrel if chambered for a 7.62x39 cartridge will work fine. Just don't take a AR10 barrel chambered in 7.62x51/308 and try to put a 7.62x39 in there as the casing wont fit properly and can explode. bullet itself will be fine. however you may notice increased wear from bi-metal jackets common with russian ammo. They tend to be harder material. at the price of their uppers though: I really wouldn't sweat it. You're definitely getting your moneys worth out of the upper.

Also their barrels are cheap...like $52 and you're back in business if you ever wear that barrel out.
 
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v0lcom13sn0w

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BCA. I know a lot of non likers of them out there but the cost was a deciding factor for a 1st time, easy conversion. I’ll see how the receiver and bolt hold up.
The lower is a S&W M&P 15.
i have had excellent results with my BCA 6.5 grendel barrel!
 
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I also did a custom build with one of their 308 barrels for my AR-308 build. barrel cost was like $78 shipped (they charge $10 shipping on all orders) and what a steal! fluted 416R socom profile 18" 1-10 twist barrel for that price...no complaints at all. I'm ringing gongs at 200yds using cheap russian ammo with an EOTech. It shoots pretty well! Have nothing but good things to say about BCA.

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Put some rounds down range through it and you'll likely be smiling ear to ear knowing how much you paid for it vs how well it shoots and operates ;)
 
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amusicman2

amusicman2

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Glad to hear that guys. I appreciate your input. I tend to get out and shoot only a couple times a month so I don’t go thru tons of cartridges but I sure am looking forward to shooting this. I also ordered a 450 Bushmaster but they sent me the wrong style (carbine and I wanted the 15” mlock) so I’m still waiting for the correct one. Really looking forward to that one. Have cartridges made for that too. Here’s the 7.62 upper on the lower. For now I just have a red dot on it.

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Buddy has a 450 bushmaster. quite a thumper those are!

For the 7.62: get yourself some C-Products mags if you want to run more than 10rd cap. 10rd mags don't really matter too much.

Also very nice getting an Mlok upper! I got the keymod cause it was only decent lookin upper they had in stock at the time (and on sale at the time for $189.99) I do recommend ditching their flash hider if you plan to shoot from a bi-pod or block and throw a brake on there. definitely not required though.

They just tend to jump up and to the side a bit otherwise. The brake keeps it planted on the bench/ground and on target while taking a little recoil out of it. Though if someone is shooting from the bench right next to you: they might not like you too much with a brake on there LOL. Lastly: Primary arms ACSS Raptor 7.62x39 scopes are pretty nice for these. ;)
 
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amusicman2

amusicman2

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Nice, I’ll check the scope out. I’ve been looking at a few scopes in the 1 or 2-7x. There’s is a lot of choices out there. I did pick up a few AR Stoner 10 rd mags also when I ordered the 450 brass and mags.

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amusicman2

amusicman2

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My rounds are just nothing too hot 125gr. Only the bullets are .308 instead of the .310-.312. Glad everyone seems to use the larger bullets in them. I also have a box of Hornady .310 123gr sp to use up then.
 
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As for the bullet: 312 is standard size for a 7.62x39 round.
It ranges from .309-.312, .310 and .311 being more common. Well, .308-.312 if you include some U.S ammo.
you may notice increased wear from bi-metal jackets common with russian ammo. They tend to be harder material.
7.62x39 isn't as fast as .223/5.56, less wear. If an AK can go well past 20k rounds before a new barrel is needed I don't see how an AR will be different.
 
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It ranges from .309-.312, .310 and .311 being more common. Well, .308-.312 if you include some U.S ammo.

7.62x39 isn't as fast as .223/5.56, less wear. If an AK can go well past 20k rounds before a new barrel is needed I don't see how an AR will be different.
Even when the barrel does wear out though (if it ever does in his lifetime): BCA barrels are cheap to replace so it shouldn't be a worry.
 
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I'd see no reason to throw away perfectly good parts if just the barrel is worn out but to each their own I guess. Why not rebuild the upper with a new barrel and buy another complete upper too?! have a spare ;)
 
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Had a little fun at the range with mine couple days ago.

Did a group at the top @50yds, then proceeded to do rapid double taps quickly to see if I could keep them all on target while emptying the magazine. Had steam rolling off the upper when I was done LOL but it was fun! I let the gun cool down after that round before letting a couple guys at the range give it a try...I think I may have converted them to 7.62x39 from 300blk lol. They were smacking the gongs at 200yds first shot every time with it too.

They let me shoot their .300blk and a .450 marlin break action as well. Good fun day at the range!

How's your rifle doin @amusicman2 ?
 
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amusicman2

amusicman2

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Funny, finally shot it with the 450 Bushmaster upper this weekend. Having a occasional feeding problem tho. Did a bore sight Friday night with the dot and with the first shot Saturday hit the 2 liter of orange pop at 50 yards. Those punch a good hole. Manageable recoil on those too. Thinking it’s a magazine issue and may have worked on it the magazine the opposite way I should have after research results at lunch today. Haven’t shot the 7.62 upper yet.
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amusicman2

amusicman2

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I was also thinking maybe a spring issue to. Slightly heavier might help push the fat cartridge up? Any ideas?
 

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