22lr ar catch22 fix it kit for m&p magazines

thingiverse

I have a dedicated 22lr upper and wanted LRBHO so I got the Catch22 bolt catch. Well.. it doesn't work! To be clear it works every time I rack the bolt manually. But doesnt work with live ammo. I read online people are JB welding a .8mm spacer onto the bottom of the bolt catch. So basically it needs to engage about 1mm higher. Some folks added something to the "pin" at the rear of the follower to push the bolt catch higher. Well.. forget that. Thanks to the wonderful world of 3d Printing and Rossdaboss702 - we can just make the pin 1-1.5mm taller. Works for me now every time! I would print 100% PETG or carbon. Just not regular PLA you don't want that thing warping in any kind of heat. Print the halves and glue together with CA, do not try to print vertically the layer lines are important. Might have to sand a little at the rear and front for smooth action of the follower. I also added my own magazine spacer. The ones from catch 22 are great but they are flat. The m&p mags have a ... shape.. to them. I used 3M VHB tape. The tape itself is about 0.6-0.7mm thick with the peel away part. Clean both sides with alcohol first and it should NOT come off. Attach it at almost the very top of the front of the mag. This I printed in black carbon petg for the color and heat resistance. On the black 15-22 mags it barely drops free, but it does. On the FDE ones, it doesn't. For some reason my FDE 15-22 mags are tighter. Go figure.