I had cast some, but due to getting married, having a child, etc. I got out of it. I am thinking of getting a few from GT bullets to try in my 358 Winchester. They have a 220 grain hollow point cast from 3% tin, 3% antimony, 94% lead. What would be the optimal speed for these? Target would be deer at 20-200 yards. I am thinking 2000fps may be about right but not sure. (may be too fast for deer in close??) Second thing I am not sure about is the gun gas a 1:12 twist. Will that limit my ability to get these up to 2000 fps? Something about RPM thresh hold? (Sorry, do not understand that one so much)