I bought a .22lr upper from PSA and plastic black dog 25 round mags. Once assembled the mags wont lock into place. If I remove the back pin and allow the upper to release from the rear of the lower I can insert a regular 5.56 mag and it will lock into place.
Do i need to remove material from the top of the notch that locks into the mag release? Or is it another issue?
Thoughts or similar experiences?

I have lots of BDM mags never a fit in lower issue (the older ones have feed lip issues, fixed in later models), so I think the first question is will the BDM mags lock in place on the lower when separated from the upper? IF so I think you have an upper issue (not unheard of with PSA).

No they won't. A regular 5.56 mag will lock in place no problem. Sounds like a mag problem

I've used the Black Dog X-Form magazines for quite a while in my 522...the old style design with the molded in feed lips will sometimes be difficult to fully seat and lock in...the newer designed X-Form (removable feed lip) locks right in, but are looser in the magwell...

In the photo you can see the difference in the newer design (lower pic) and the older origional design (top pic)...the X-Form magazine looks pretty much like a 20 round GI AR magazine...

I'm not sure which style you have...but you might contact BDM...they have always been great to work with when I had a problem with cracked feed lips on the old style...they replaced them with updated X-Form magazines...

This message has been edited. Last edited by: Bisleyblackhawk,

Same advice I always give. I used BDM's for awhile. Then I bought a Boonie Packer Better Mag insert, about 30ish bucks, slides into magwell and converts it to use S&W 15-22 mags. Costs a little up front but you will be happier in the end.