Lee Loader

I just bought a 308 AR10 and am getting geared up to load some ammo for it. The question is do I need to crimp the rounds. I usually full length resize and then use a 21st century expander mandrel to get 2k under bullet size neck tension for my bolt 6.5 CM. I am somewhat concerned about the AR and just using neck tension to hold the bullet in the case. What do y'all think.

I haven't had to in the Armalite Model 15 types but the model 10 may be more agressive beating up cartridges in the mags .

The only thing I crimp is lever gun ammo for the tubular mags .

An FCD will be your go to tool here if you decide to do it .

Thanks. I usually crimp .223 rounds lightly. I do use the FCD for that and will use one on the .308. I was concerned about the AR10 being harder on the rounds like you said.

I load 308 for the AR10. Each brass, of course, gets full length sized. I do not crimp at all. There is sufficient neck tension to prevent any projectile movement in the case when situated in the magazine.

Bayou