Lee Precision Factory Crimp Die
This is Lee Precision's Factory Crimp Die. A lot of people rant and rave about the increase in accuracy or decrease in extreme spread in velocity over the chronograph using this die does for them. Lee Precision's Factory Crimp die seems to be a favorite of guys who don't even like all the other dies Lee Precision makes. And for the price...trying it out seems to be a no brainer.
"Lee 300 AAC Blackout Factory Crimp Die crimps the bullet in place more firmly than any other tool. Tests demonstrate that even bullets which have no crimp groove will shoot more accurately. A firm crimp improves accuracy because pressure must build to a higher level before the bullet begins to move. This higher start pressure insures a more uniform pressure curve and less velocity variation."---from Lee Precision's own website.