Marko has a good post up discussing why reliability is the most important criteria for a carry gun. I would like to take this opportunity to expand on that a little bit.
All my .45 ACP 1911-type carry guns are absolutely reliable with Wilson 47D magazines. They will all feed 230gr ball, 200gr SWC from Georgia Arms, and 230gr Remington Golden Sabers with one hundred percent reliability.
"But, Tam," you say, "How do you know they're reliable? Will they feed Aguila IQ? Will they feed X-treemShok from 10-round PowerMags? Will they feed Nytrillium hollowpoints from Chinese knockoff GI magazines?"
I don't know.
Nor am I likely to ever find out.
Because I don't put that crap in my guns.
Look, the odds of me standing over some dead zombie terrorist in the jungles of Zimbabwe, forced to use his ammo since I'm out, and him being coincidentally armed with a 1911 which I apparently can't use because I shot him right in the gun, and it turns out that Dr. Evil has armed his zombie terrorist henchmen with surplus Colt mags full of Glaser Safety Slugs that won't feed in my gun, are... well... "ludicrous" doesn't begin to cover it.
I buy my own mags and ammunition. I buy the same kinds of mags and ammunition every time. I buy them in bulk. I buy them because I know they work in my gun, not because they had a cool ad with rapelling ninjas in Guns & Ammo this month or because they have a 98.6% "One Shot Stop" rating or because SquEAL Team Six uses them or whatever.
I have yet to be convinced that this is an unsound practice to follow...