Have a pistol? Also get one in 22 lr. Have a Ar15 or AK? Get one in 22lr too.
A box of 550 rds of 22lr cost 20 bucks at walmart. I always make sure I spend at least half my time on the 22lr and the rest on other calibers. It makes your other expensive caliber rds last twice as long.
Me and my friend shared a box of 550 rds of 22lr the last time we was at the range. Non stop shooting with barely any break, and he only brought 100 rds of 9mm. While I was mixing it up with 9mm and 45. After 2 hrs later, we finally finished that box and at that point we were tired of shooting. Cant beat that.
Imagine if I shot strictly 9mm and 45 for 2 hrs straight. Would have cost alot.

