ultra magnus wrote:
How do double barrel shotguns avoid this?
Bingo. We have a winner.
According to ATF if it fires more than one round per trigger pull that's what it is.
Still looks fun though. Can you imagine what a conversation starter that would be.
Every double barrel shotgun I have ever seen has had either:
A) One trigger
that lights each barrel off sequentially with each pull of the trigger.
B) Two triggers
, one to actuate each barrel.
EDIT(ed for clarity): To more completely address what I think you are really asking (upon reflection):As an example; if we imagine a double barrel shotgun having one trigger that (either by design, modification or intentional malfunction) ignites more than a one (1) cartridge with each conscious activation of the trigger, you would be correct in acknowledging that firearm to be (under the law) a machinegun and regarded as a highly legislated device.
As a side note: accidents of this nature have been know to happen on very rare occasions with some older double barrel shotguns that I do not know the name of.
IIRC In the instances I read about they were considered to be 'slamfire' and not 'full automatic' as it was caused by the mechanical malfunction of the FCG.
It's a different story altogether when the gun (or a component) is designed to fire more than a single cartridge or shell.