Better-Mag M&P 15-22 Magazine Adaptor

I finally had a chance to try this thing. Awesome! Requires no mods to the lower (like cutting coils off the bolt catch spring) and there's no need to tune or tinker with it to get it to work. My old CMMG BHOA adapter took a lot of tinkering to get working and even then it wasn't 100%. With the Better-Mag adapter you just drop it in the lower and go. The bolt holds open on the last shot every time. I ran about 15 mags through it and never had a failure to lock open on the last round. If you want to revert back to using standard ceiner-style mags, all you do is remove the adapter.

Only caveat is your lower's mag well needs to be in spec since the adapter goes inside the mag well. The Olympic Arms lower that I normally use with my .22lr upper seems to be out of spec (imagine that) and the Better-Mag adapter would not fit inside. Good thing I have other lowers. Stock up on 25 round M&P 15-22 mags while you still can!

http://www.redi-mag.com/images/produ...2_BMA_II_3.jpg

http://www.redi-mag.com/index.php?l=product_detail&p=52

you can run 15/22 mags without this adapter in the 22 conversions

But you can't use the bolt catch or have the bolt lock open on the last round, that's what this does. Now the entire AR manual of arms works in a .22 conversion reliably. The only other option was the CMMG BHOA and it left a lot to be desired.

Quote:

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Originally Posted by cofi

you can run 15/22 mags without this adapter in the 22 conversions

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Also, without an adapter or something to shim the 15-22 mags, they'll lock into a regular magwell and function, but they'll be loose. S&W made the magwell of the 15-22 smaller than a standard AR magwell, and made the 15-22 mags shorter by 2mm, front-to-back, to fit.

This adapter definitely takes out any looseness. Everything fits properly. The only real complaint is, like normal ceiner mags, you cannot use the mag as a monopod. Doing so will induce failures to eject since the feed lips hit the spent casing before it reaches the ejector. I was hoping the adapter would keep the mag from getting inserted too far when you lean on it but this is a minor complaint. Getting the bolt catch to work reliably was the primary goal.