I bought a nw BX25 and a used one at a gun show. The used one was not all that reliable, and even the new one occasionally had a hiccup. I took 'em apart (pretty easy--just take out the bottom screw) and cleaned them. Now no problems. BX15s are disassembled the same way.I must be the unlucky one, because I have four Ruger BX-25 mags and every one of them jams. I get the common feeding issue where the round doesn't want to pop up all the way, so the nose digs into the front of the feed lip. There is a "fix" posted online where you can make a bushing out of a cut-down .22 case that supposedly helps support the follower, but I tried it on all my mags and they still won't work. So from now on only original 10-round rotary mags for me. No sense trying to play Rambo if the rifle keeps stopping every 5 or 6 rounds.