Re: Defensive ammo
Stick with the major players.
Winchester Rangers/PDX-1
Hornady CD/TAP
Remington GS Bonded
Speer Gold Dots
Corbon
Those are your premiums. I have yet to hear bad stuff about any of these. There are other "generic" JHP bullets. The Winchester white-box JHPs, for example, are better than FMJ for expansion, but not the most reliable or consistant in its expansion. I also like bonded jackets if its available.
Manufacturers don't like steel cases. Its beleived that steel case can cause excessive wear in the chambers. This would negate the warranty. I know people who have used them in the past, steel cases usually have a coating, or plating of some sort to minimize this. I have no idea to what extent this goes. I never shot steel cased ammo, never had the need to. I know you cant use it for reloading. I just wouldnt bother with it if the gun maker says dont use it. They have their reasons, its not something that can oppress your options.