If 2 3/4 inches is a "round", that's fine. Someone else said they had an 8 round magazine on a short-barreled shotgun.
I suspect those are the 12ga Short variety. But does that count as a "round"? If it does, then will they start regulating magazines according to how many of those it will hold?
I don't think they give a rat's patootie what size is the standard.
They simply want to pass legislation that an X amount of shells is not acceptable in that scattergun.
Then they will simply tweak for less and less capacity, until only single shot shooters will be tolerated, then only muzzle loaders.They simply wish to remove firearms from people like....you!
Probably. But all of them count as a round. Makers just choose to select the standard length one as the one they use to say how many rounds will fit in a tube magazine. Much like a lever action carbine in .38 Special/.357 Magnum, which also has a tube mag - the manufacturer specs it with the shorter, ‘standard’ round.
Also, no, 2 3/4” is not 12ga Short. 12gs Short is mostly an obsolete measure, but they were 2”, 2 1/4” and 2 1/2”. 2 3/4” is and has been the standard for the past 40 years. Retail stores carry 2 3/4” and 3” and occasionally the 3.5”, but the 2.75” is what they will hand you if you go in and ask for some 12ga shotgun shells.
S&W 916A has a 19 inch barrel and holds 7 in the mag and one in the chamber. (2 3/4”) it has a 3” chamber and the mag will hold only 6 of those. It was a decent gun. That is until that terrible boating accident.