Loaded up 20 at different powder weights using CFE Powder and for the life of me I cannot remember my numbers, but I will get them and post them later if anyone wants them. I loaded some Sierra Blitzkings 55 grain and FMJ 55 grain.
Both with the same powder loads seated the FMJs at 2.20 and the shot great. 5 shot groups better then I can shoot, I wish I could see a real difference. The lightest powder group was the worst but after that they all looked great to me, but when the range is busy I dont feel like I have the time to really sit down on the bench and measure my groups like I want at least since I started reloading.
I did notice that the crimped ones did not show any major improvement and I measured the last round before I shot it twice and it was still 2.20. So they didnt shorten up.
So I guess I am going no crimp at least until I see something different. You are right though they sure looked pretty.