Originally Posted by JonM
I dont see a need to crimp 223/556 unless your chambering the same round over and over.
Jon, I will respectfully disagree; concerning ammunition to be used in a semi-
automatic I strongly urge crimping bullets. Cartridges will get rattled around
in a magazine and the bullet can get pushed back into the case at that point;
or as the cartridge is being fed into the chamber, the bullet could hit some
part of the action it could get set back in the case. In either situation that could
result in high chamber pressures due to reduced volume in the case.
This could also happen in magazine fed bolt actions, but is less likely.
In addtion, I like the Lee Factory crimp dies as they do not require a
cannalure, also the amount of crimp can be easily adjusted and with
rifle (collet) style dies all of the force is normal (90°) to the long axis
of the cartridge.