Would this be a 14 bore or a tight 12?

Nothing?

Just from the image, I read the bore measurement is 14 bore while the muzzle is 14 bore, which had a range from 0.680" - 0.690" - 0.693". Now I cannot say a 'bout the chamber. Does the chamber easily receive a 12 bore cartridge?

Cheers,

Raimey
rse

My Syracuse Arms Serial# 264xx has the exact barrel proofs it receive and shoots 12 gauge shotgun shells.

What you are looking at are the proof marks for the bore, not the chamber. However at this time (1874 to 1887) there was no chamber mark (a number in a diamond) so without a chamber gauge, you are left with trying out cartridges in the chamber until you find the right one!
You can derive no helpful information on the chamber size from these proof marks.
What is interesting about this mark, which may have passed you by, is that it is a variant on the NOT FOR BALL mark that was present where an appreciable amount of choke was present, as proofed.
However, when the barrel was not choked as we know it nowadays, but 'recess' or 'jug' choked, it could have the same bore size at breech and muzzle hence the '14B 14M' but was still choked.
There was no need to be worried about using a ball so it could be marked 'CHOKE' rather than 'NOT FOR BALL'.

I noticed the "choke" but had no idea it was for a jug choke. I had thought the 14b/14m and choke meant it had choke but still measured within the 14 spec at the muzzle. Thank you for the clarification.

What length 12 gauge shells would be my next question?

Thanks guys, so a chambered 12ga can have 14 bore tubes?

Yes, I have owned several configured that way.


Steve

would the idea be to have a tighter bore for better gas seal and longer distance?

I’ve 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

and there once was a 14 gauge gun, chambered for 14 gauge shells...

http://www.dogsanddoubles.com/2013/02/the-14-gauge-no-one-ever-loved-it/

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!

I see a 12/14 Greener Police shell listed on the Rocky Mountain ammo list. Could this be the 12/14 that the thread is about?

The 12/14 that I’m aware of was a brass case with 12ga diameter base with the forward 2/3 of the case being 14ga diameter. (Think bottlenecked rifle cartridge) The idea was if a bad guy stole the Police gun there was no commercially available ammo that would fit the gun. The 12/14 was the answer to the previous idea of using a regular 14ga case. The bad guys figured out you can shoot a readily available 16ga shell in it just fine.

No it was Lewis hammer gun

I believe I bought the Lewis hammer gun you refer too. It didn't sell and I made an offer they took. If nothing else gauge chamber reducer inserts will be used with RST low pressure shells. the fore end has to go as well as the pad.

Yes that was the one, I was very curious about that one! Please let us know if it really has 3inch chambers? That forend is pretty bad. I would just reshape it, at least it matches the the stock!

The chambers gave me some thought but as I read about Lewis shotguns they did make 3 in. chambers but I dought at that time period. Its' to bad they screwed the fore arm up the stock and checkering was pretty well done. I will contact you when it comes.

Cool, I had reservations about 3 inch chambers in the 1870’s, would be curious the thickness of the barrels at the forcing. Please keep me posted! Lewis has been on the search list for awhile now!

RARiddell:
You have a message.
pod

See this line - French shotguns from 1875-1900 proofed for shells up to 90mm.

https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=516435&page=2

Just to illustrate the point, here is a Didier-Drevet barrel, 16 gauge which looks to be chambered for 8.0. It is double proofed in Saint-Etienne for PS powder so it is pre-1900 and it does not have the 1900 prize marked on DD barrels but rather 1855, the date of his original gold medal at the Paris Universelle. Barrel is Damascus. It is post 1889 since chamber is marked in cm. (The barrel oddly is not dated or I cant read it.