9mm AR Build

Gunsmithing 80% Builds
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I put a Blitzkrieg buffer in mine with an extra power JP carbine spring and a CMMG 9mm bolt and mine works flawlessly even with sub sonic loads

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Welcome @dwid13
Great to have you here at Full 30

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Is it possible to get a video of the ejection? Perhaps it’s not flipping it out right. Did you clean the BCG? I run an MVB industries buffer and have no problems.

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Ill see what I can do. This set up seems to be working for others. I am clearly doing something wrong.

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Check your ammo as well, not that it’s low on power. I’ve run the federal aluminum 115gr without any issues.

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You might want to try a heavier buffer. Cheapest option.

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That was my first thought as well. I have a heavy buffer on the way. We’ll see how that works. Ill make sure to keep y’all posted!

Thank you very much @switchpod

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I was shooting some Nevada ammunition reloads, so that may have been an issue as well.
I had a few bursts that cycled, but not many.

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I would start with different ammo and see how that works.

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I’ll see if @SuppressedNationJoey can fill you in on what he’s running. His has ran flawless and ate everything we’ve fed it

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I’m running the KAW Valley bcg with 6.5oz extra longer buffer and spring. The spring and buffer are a kit from Brownells item #100-027-720WB. Been running subs-normal loads without a single failure.

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Bingo! Gotta go heavy with 9mm.

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Mine was the opposite. Way too light and chewed up the buffer after putting 250 rds through it

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@Greenwell_Armory

If you build it, they will come!
Building a heavy buffer!!!!! Sig 716 - #2 by switchpod

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Yep. Swapping the buffer as we speak. Ill let you guys know how it went after I shoot it this afternoon.

Thanks for the advice y’all!

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So the weighted buffer did help, but out of 10 shots I’m still catching at least one empty on the way out. I used three different types of ammo. Winchester white, Nevada Ammo 9mm reloads, and some Fiocchi they had at the range. Though the Winchester worked the best, its still not as reliable as I would like.

So… Whats everyone running for spring weight?
I’m going to try to zip tie this spring down for a few days and see what that does. But a more precise solution would be preferred.

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How heavy is the buffer you have now?

You most likely have a 17lb spring In it.

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Running the Kak 10 oz. buffer right now.

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No kidding. How does the ejector look?

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Ejector looks fine. It seems like the bolt is just getting there to quickly. None of the casings had the same marks. They are just getting caught by the bolt on the way out every six shots or so.

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