[Arkansas Toothpick]

More myths—

-Pulling back the slide on a semi-auto or auto way more times than necessary
-Blowing up a car with a few shots from a small arm
-Shooting off a lock on a door (possible, I guess, but probably not as easy as Hollywood makes it look)

[GonzoGOP]

-Shooting off a lock on a door (possible, I guess, but probably not as easy as Hollywood makes it look)

That was probably the only "Gun Myth" that the Mythbusters confirmed. One round from a .357 and a deadbolt lock was sufficiently damaged that a kick popped it right out of the door. Shotguns worked even better for door breaching.

Note that it wasn't the lock that gave way, it was the wood where the lock was attached. Hitting the lock with a good sized hammer would probably have a similar effect.

[Abathar]

I remember seeing a spoof of the old commercial where they shoot a lock with a high powered rifle and then showed it still staying locked afterword.

The commercial started out the same, guy loading the gun, crosshairs on the lock, but when he fired the lock just disintegrated all over the place. The screen then showed “Sorry boys, this time it was a Weatherby” and the guy was holding a nice Mark V magnum with a smile.

I figured out how they did it, they hung the lock on a steel plate target instead of wood like the original commercial, the bullet splash is what tore the hell out of the lock.

[andyk]

Pulling back the slide on a semi-auto or auto way more times than necessary

I think that's the most prolific, most obvious, and most deceptive of all the firearm myths.