How do I change frame for sprite

I have a pickup, which change frames randomly and five bullet frames.

When, main charecter is on collision with pickup, my bullet frames changes , but once. (pickup frame1 = bullet frame 1,pickup frame 2 = bullet frame 2 and etc...)

How to make, collisions constantly?

do u want to fire all 5 bullets while collision with main character or is ur bullet is animating with all bullets.