I load Silver both at home and on the street. Rest of the family loads blue.
I have tested Glasers enough, to trust my life to them! (I use to work for the medical examiner of a large populous southwest county, so I have seen a few gunshot wounds!) A rounds effectiveness is multi-factorial, but the ability to quickly drop blood pressuer is all important. Using multiple pellets, you have a greater chance of hitting a major blood vessel. If you struck something like an upraised arm, the shotgun style wound and blood loss alone, would probably change the perps mind. If not, just fire again.....
Do fire enough practice rounds to be sure an automatic will cycle them properly!!!