I have the same thing, slide is very hard to release on an empty mag....colt mags that came with the firearm. I haven't fired it yet since I got it but won't try to remedy the situation until I try it out first.CowBoyWay said:I then noticed that with an empty mag and the slide retracted, it took a lot of force on the slide release to get it to release. I removed the slide stop/release and noticed that the rear face where it contacts the magazine was irregular and not true. I filed and polished it to the extent that it would easily release the slide with an empty mag. I just returned from the range and had zero malfuntions. Hope that helps.