Yet another way to make 300-221 fireball brass

[fireball168]

I've used a Wilson case trimmer collet/sleeve.

Put a dab of Dykem on the case, scratch the Dykem with your caliber at the length you want to trim it.

Chuck up the Wilson trimmer collet/sleeve in 3-jaw chuck, put an end mill in your tailstock - advance the tailstock, it'll trim one in about 5 seconds.

Finish the trim in your case trimmer of choice after full length sizing/forming.

Saves some wear and tear, and sure seems much quicker to me.