Sometimes after you hit the ground and start looting some of the guns don't load right away, just the ammo loads, or soometimes the guns load but not the ammo. Also riflea seem to load in before shotguns and hellfires. This happens a lot and is really irritating on these extremely crowded drops in Fives. A lot of bugs to fix.....a lot!
Try and get used to it. Daybreak won't fix this. A fast paced game where you need to wait for guns to appear... Crazy uh?!!??!