My rule is three loads for each gun (1 in, and 2 reloads) So for semi-auto's 3 magazines, and revolvers 2 speedloaders. That said, I have six mags for my XD9, four for my P6, four for my Mak, two speedloaders for my SP101, and I'm working on finding a second spare mag for my Beretta 21A.
I...