I have a 4516 (can't recall at the moment whether its a dash one or two but I think its a two) but I do know that the issue seems to be with using the correct mags for the gun. My age is showing as i can't recall the exact way that it works (others will help) but i do know that my 4516 is an absolutely top notch .45, if not a bit heavy. To me the 4516 is a classic and even if the one that you are looking at is finicky about mags (I'm pretty sure it is the 4516-1) it is worth the effort and possibly the later mags are fine for use. It may be that the earlier mags will only work in the 4516-1, but as I said, others will help. One way or the other, well worth it.