My department lets me choose between three 40 cal weapons. Beretta 96, Smith&Wessom M&P-40 or Glock model 22. The S&W gave me problems so I switched to the Glock. During practice sessions using 124 grain plated bullets from Rainier I got very large groups and alot of keyholed bullet strikes. I assume the Glock barrel doesn't like the plated bullets. I tried several loads with several powders and it was always the same. What would be a good barrel that I can put in this weapon that will let me shoot all bullet types? I need a drop in barrel that is of good quality. If I am staking my life on a pistol I want pinpoint accuracy and 100% reliability.