Bought some 25 Rd Butler Creek mags..... Mistake..
Had frequent shell flip up jams. I've put the .22 bushing fix in Ruger mags but BC are glued.
I put 25 rounds in a mag, marked where center of the shell follower was and where I wanted to put the bushing in. Removed several shells, drilled a 3/8" hole where marked. Put the shells back in and shoved a bushing through the hole into and over the spring stud in the follower.
I've found over 20 shells in the mags put to much spring pressure. Load around 20 and it's quite reliable.
I was very close to tossing them in the trash. I have a sage rat shoot coming up and they will get a serious test.
Hope this helps you if the also bought "bargain mags".