Ive never owned a 12 gauge with 14 gauge bore in the tubes, but, have owned several that were 11 gauge. I suppose the quest was to improve the performance of ammunition that was still loaded with felt wads and an actual explosive (black powder) propellant. I believe the 12 20 concept took that to an extreme, but, have never owned one of those guns, either.
Maybe someone, here, has and can report how it works?
I think a lot of the magic bore and choke enhancements that were promoted and sold over the years were no more than marketing hype.
Best,
Ted
You are confusing the 12/20 with the vena contractor (probably spelt wrong).
The 12/20 was bored as a normal 12b but was lightweight due to the back action Baker lockwork, hence a 12b with the weight of a 20b. Well not quite that lite but you understand the marketing.
The vena contractor was chambered for a 12b but the bore contracted from 12b to 20b at the muzzle. Apparently is worked okay, didn't blow barrels and the recoil was acceptable. Not a success though!
I think the idea behind 12b's bored 14b was longevity: thick set of tubes bored tight had lots of wall thickness for lapping out pitting and reproof.
I may be wrong, it might have been all about what was on hand when they needed a 12b!
