How's it going , I was interested in purhasing a 15 rd mag for my 45 Acp rock island , but I noticed just about everyone had jam issues with them . I was at the true value looking at guns etc. and I noticed they had one for 15 bucks . So I bought it . I first wanted to see how easy the rounds exited the mag by pushing them forward with my thumb before I inserted it into the 1911. I noticed that the rds were hitting very low on the front of the mag and I could not even push a rd out with out lifting the front of the rd with my other thumb . So I looked at my Novak mags and noticed that the front of the mag was cut lower were the rd exits the mag . So after doing some dremel work I filed the mag to the same shape as the Novak and the 15 rd promag works flawlessly . I forgot to mention that before doing the dremel work I inserted the mag into my rock island and began trying to chamber a rd .i repeated that procedure to see how it fed and as I expected many rds jammed and the ones that fed did so very rough . I also did work on the cheaper 7 rd mags before I used them and had never had an issue with jamming . I would apreciate some replies on the matter if possible thanks .