Last Sunday, I shot a pin and plate match at a local range. One of the shooters had a .22LR AR SBR. His SBR uses M&P 15-22 magazines. I asked him how this was possible and he showed me the magazine adapter called “Better Mag”. It is made by Redimag and allows for the use of S&W M&P 15-22 magazines in almost any AR-15 magwell. The adapter will even hold the bolt open on the last round.
Here is a video that details the installation.
The Bettermag retails for $39.95 and can be purchased on Redimag’s website.