No, Jaws was killed by an exploding O2 bottle. The Garand bullet caused the explosion, but the bottle was what went boom. Jaws 2 died from electrocution while Jaws 3 died from a grenade of some sort.
The Garand was employed against Jaws early on, but the bullet didn't kill it, and the rifle was short-stroking so Quint didn't get many rounds off. Quint, of course, was eaten by the shark, and Brody shoved the O2 tank into its mouth to keep from being eaten himself. Only during the Orca's sinking did Brody manage the shot, which was his last one of many, that detonated the tank and send the bloody corpse to the bottom of the sea.
Ash