I load and shoot a lot of 45 Colt and 45 Casull ammo. I cast, size and lube my own bullets. I have tried most of the popular bullet designs with good results. My current favorite, especially when I want to push velocities a bit, is the 45-300AG design from Tom over at Accurate Molds. It will regularly shoot under 4", 100 yard, 5-shot groups out of my FA83 -- either in 45 Colt or Casull cases. And, it works great in my Rugers and USFA revolvers where it is as accurate (or more so) than any other design. It is an added step and expense to use the gas checks, but that is all I am using lately. Some folks say GC's are unnecessary in the 45 Colt. Maybe ... but I like them so I use them.