at the time, early 80's, the knock on silvertips was that the jacket material/plating was clogging the gas port/cylinder...same problem with the lead or dirty powders.
i'm currently feeding my p7 the ranger SXT 127gr +p JHP, but my default 9mm round has always been the federal 9BP 115gr JHP
i'm currently feeding my p7 the ranger SXT 127gr +p JHP, but my default 9mm round has always been the federal 9BP 115gr JHP