i have been running the mag that came w/ my (non stainless steel) kit like crazy and letting other people try it and running it more.......i don't really even know how many thousands of rounds (maybe 12k-ish) i have run thru my first mag and it has only jammed maybe 10 times TOTAL and they were all from bad rounds or dirty kit. (waaaaaaay better than the dedicated S&W my buddy has btw) however, when i got this mag i was noticing that their are nubs on the backside of it to make it sit firmly in the magwell.also it came w/ a slip that said to file off the nubs if it didn't run smoothly. i tried to run it but it kept jamming and double feeding. so i filed the nubs off completly and ran it again. it jammed much less and seemed as tho it was starting to seat in the spring a little better. it was running smoother the more i ran it. i am thinking of actually shooting a bit of graphite into it b4 i run it next time as the orignal mag feels smoother if u push the plate down w/your finger. also the spring feels much tighter than the one that runs great. i actualy breathe a lil easier knowing i have more than one of these mags now as this conversion kit is by far the best investment i have made as far as fun trigger time vs. $$$ EVER.
I recently bought a CMMG Alpha conversion unit for my AR and included four of these mags. I really didn't expect any of them to work - but was more than pleasantly surprised. Flawless! The mags are a bit tough to load once you get into the 18-round range, but I managed go get 25 into each one. Then at the range - not a single jam, FTF, FTE - nothing. Ran all four dry - reloaded - did it again. Could not be more pleased with this cheap alternative to .223. Highly recommended.
I have a Stag AR-15 with their .22LR conversion kit. This looks like the same mag that came with the kit. It's terrible. It requires that you take a knife and trim down a tab until you get a snug fit. The mag doesn't easily slide in and out compared to the other mags that I bought. The other brand required no trimming, snap right in and out without hanging up, and they are translucent so you can see how many rounds you have left. You're working blind with this mag. I haven't used it since I received the replacements.