I currently have a PSA AR 300 Blackout.
I wanna buy a new 8" 9mm upper and use Mean Arms Endomags to shoot some 9mm ammo (cheaper). Will that be a reliable setup?
Do I need to change the buffer tube spring?
Thanks
I have seen the Endomags work well, personally I use the PSA magazine block for Glock magazines. It hasn’t jammed once with anything from 115gr to 150gr ammo. It also ran flawlessly with an FRT.
With a standard AR15 buffer and spring there can be some bolt overtravel that can result in the key on top of the BCG to hit the rear of the lower, it can knock the key loose. The best solution is to get a 9mm buffer that is about 3/4 inches longer so the buffer bottoms out. My 9mm upper is always ran suppressed so I use a 11.5 oz AR45 buffer with a standard AR15 spring.
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I didn’t realize PSA had a version. Can’t find via store search. Any chance you have a link handy? Flirting with the idea of converting an existing lower for pcc use myself atm.
Endo mags work great. Go for it!
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Good to know. My main concern is the buffer spring and weight.
If I should leave the one my PSA AR 300 blackout came with or swap it out.
Definitely swap it out. 9mm is blowback. You are going to need a 9mm heavy buffer.
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What weight will I need? Do I need just the weight or the spring too? Any links?
I’m new to this ar stuff and especially swapping parts…but it’s fun…haha
Thanks
There are ALOT of factors with 9mm. I would get an extended heavy 9mm buffer such as this as a starter…you may eventually need a heavier spring also, but try one thing at a time.
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