Why is the minimum length for a rifle barrel sixteen inches, but the minimum allowed for a shotgun is eighteen inches? Why not the same length for both? This has always puzzled me.

The minimum barrel length for both was originally 18".

The NFA was later amended to make 16" the minimum for rimfire rifles years later, and eventually it was amended to allow 16" to apply to all rifles, but shotguns weren't addressed either time and remain at the original 18".

2 inches of additional barrel length isn't going to make a difference on a shotgun... They just neglected to change that when they were changing the length for rifles along the way.

Stuff like this happens all the time when laws are getting amended. Remnants, exceptions, loopholes, contradictions, and unintended ripple effects abound, generally because the folks making the changes don't bother to fully understand what they're changing and its interactions and repercussions.

That’s very interesting. A sixteen inch barreled shotgun would almost make the concept of the Remington Tac-14 superfluous.

The length was amended from 18" to 16" in 1960 due to surplus rifles that were a little short:

17.875" - 18.125" M1 carbines, Swedish Mausers with 17.5" length barrels (M96 carbines).

Remember back then and earlier people thought longer barrels were more accurate. That is sort of true in the respect that a longer barrel can produce higher velocities (to a point) and thus flatter trajectories, but inherent accuracy can be better with shorter stiffer barrels.

quote:

Originally posted by Lefty Sig:
The length was amended from 18" to 16" in 1960 due to surplus rifles that were a little short:

17.875" - 18.125" M1 carbines, Swedish Mausers with 17.5" length barrels (M96 carbines).

Thanks, both of you, for the education.

Thanks for asking that Club, I have also wondered about that also.