Hope this isn't too dense a question...
There are a million (o.k. just shy of that) pistol brands, models. gases...when someone wants to get more mags do you have to by specifically for one brand, model and gas or is there something more common like the M4 mags in the rifle world?
Also, lots of talk of cross border importing, but are mags an issue? I wouldn't have thought so, but would be interested to hear.