I've had a few 10 rnd aluminum mags from Pro Mag. I've used them to shoot at least 300 rnds through my springfield 1911. Recently an issue came up while I was at the range. I pull the slide back and in only goes forward about a 1/4 inch. I've tried locking the slide back and removing the mag, but the mag wouldn't release. And only after pulling the slide back 3 more times did it finally load and was capable of firing. It only happens with the first rnd though, but still rather annoying. I've had the issue before with 15 rnd mags but the 10 rnd mags worked fine up until now. Just looking for some assistance.