» Mon Jul 19, 2010 5:22 pm
Answer to directly above: In your items page, once you have a gun selected, scroll over to the ammo list and the ammo types that you can use with that weapon will be bright.
To OP: Yea, its useful if you can get some Primers, which are unique to the gun type (small pistol, large pistol, ect.).The shells come naturally, and you can buy jars of powder from the gun runner outpost next to that New Vegas border neighborhood.