I haven't bought a ProMag in years, so maybe their quality has improved, but the last one I bought (for a Mini-14) didn't fit well, and always gave failures to feed. OTOH, a couple of years ago, I bought a Triple K mag (with a lot of trepidation) for a Sauer 38H for a friend, and it fit and functions fine. I only bought it because the 38H factory mags are scarce, even scarcer than 4506 ones I bet. Between my experience and biku324's, I'd say six of one, half dozen of the other.