I hunt a lot with my AR and have used a lot of different 5 rndrs, and I only use ALL METAL mags. Bushmasters makes some that work well, as well as Colt, and they are all metal standard 20 rnd size with a stopper inside to limit them to 5 rnds. I recently ordered some 5 rndrs off of 44mag.com, the ProMag 5 rndr that is 20 rnd size and also the "flush fit" mags from National Mags. By the way, these are not flush fit! They go up in the mag well over half way! Plus they look and feel cheap; however, I have been using mine without a hitch for a couple months. It is a great extra mag for a pocket on my hunting coat because it is small and doesn't poke me. You shouldn't have a problem finding any all metal mags - I ordered my Bushy right from them, got my Colt from a gun show, and obviously the other 2 came from 44mag.com.