I tried crimping, and using bullets with a cannulure in my Mod 12 Savave LRPV. I also used the same bullets not crimped. I also used some without cannulures as well.
Die used was an RCBS .223 Rem for crimping. I also backed it off to seat without crimping. The other die used was Lee Dead Length seating die. It does not crimp at all.
Results were that the uncrimped rounds regardless of die used grouped under .5 MOA for 10 groups of each shot. The crimped rounds grouped and average of .95 MOA with the smallest of 10 groups being .85 MOA.
My testing was for my purpouses. I do not compete, I punch holes in paper. I handle the occasional predatory varmint for friends. I do no like to miss, and very seldom in life have I ever missed on a shot.
When it is all said and done. Use what works for you.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.