This project offers free sound effects for weapons. For example: sword and hammer impact sounds (modified from starcraft2), shotgun sounds, sniper rifle sounds, high quality gauss rifle sound and much more. If you want to make a weapon that shots very fast (5+ times per second) just download one of the sound packs. You can also download epic realistic gauss rifle sound effects (modified from starcraft2).
Rifle Sound Pack
Pistol Sound Pack