9mm Upper

PSA Products AR-15
1

I recently purchased a PSA AR-15 pistol lower and am looking for something to hang on it.

Since the PSA 22LR upper is currently unavailable, I have been looking at PSA GEN4 9mm uppers. One of the comments I have read said that you need a conversion kit to mount one of these uppers on an AR-15 lower.

Can anyone elaborate more on this “conversion kit” or what is needed to run one of the uppers?

TIA -

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2

You need a 9mm mag adaptor to use a standard ar15 lower. Also, the buffer for 9mm is different, and depending on which one you use you will need a buffer spacer (although some folks use quarters or nylon spacers) to prevent your mag catch from breaking.

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3

GuitarGuy, I have a 9mm PSA upper that I plan on using an ar lower. I have a heavier buffer and some Endo mags from Mean Arms. I’m not clear about the mag catch breaking.

4

@dewildeman 9mm bcgs can overtravel due to the way they are designed (the bcg is also the bolt). Too much over travel can cause them to slam into the bolt catch and break it. There are spacers you can buy, some use quarters, and/or you can use a buffer that is extended.

5

Thanks!

6

How does one tell the difference between a 9mm buffer and a regular buffer. I have a 9mm lower in hand with a 9mm pistol upper kit ordered and on the way. Am I set?

Thanks

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7

9mm buffers are usually way heavier. 5oz and up. Some are extended (Google it and you will see).

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8

Thanks @GuitarGuy. I will google it for more research.

Stocking up and storing away.

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