I measured an older sxs hammer gun for a customer. The gun was made in Batavia NY. The chambers accept my inserts that I made to specs i.e. 10 ga.shells;however the barrels measure .744".The barrels have been tampered, that is: long forcing cones and way too smooth damascus bores.What is the verdict?

That gun is out of proof since it sounds like someone did some pit removal? Oops, I forgot Americans use tire and string test.
Gee, do you think it's one of them experimental 10/12 guns.

Perhaps.But on a standard 10 ga.the bores would have started at .775. So,how does one hone them down to .744?

Sorry, please disregard my post. I'm like a fish out of water on this one.

I have old American doubles with bores all over the place. On the loose side I have an 1889 12-gauge Parker Bros. that has bores .757", and I have my Father's old 1896 vintage Remington AE-Grade that has bores .744". On the tight side I have a Baker $100 Pigeon Gun 10-gauge with bores .750" and my Fox Gun Co., Balto., MD., U.S.A. 12-gauge has a right bore of .712" and a left bore of .708"?!?

You guys might better get those bOre gauges checked....

Homeless,the gauges-gages are checked against a known standard as in other gauges and known wire sizes.After reading your other posts, how are you checked?

lol...I bet they're Teague lined.

Wrong bet. No liners.You lose.No game. Why 10 ga. chambers; 12 ga. barrels?

I bet they're leaded real bad....

Better idea....yOu tell us.

Didn't Lang make a 20 bore with 12 gauge chambers? Maybe a version of the same idea - 10 chambers with 12 bore. I really don't have any historic record or even an article to support this but sure is interesting. Would be nice to see a photo to see how thick the chamber walls are.

I will ask the owner to bring the gun back and I will measure the wall thickness. As in a better idea--,if I knew the answer, I would not have asked.d U h.

To start the elimination proccess, a measurement of the wall thickness and the designation stamped on the watertable or barrels flats will be needed.

Kind Regards,

Raimey
rse

A question much like this came up some several months ago. The question was from me.
I had looked at a gun that had 16 gauge chambers and 20 gauge barrels. Walls were right as were the bore sizes, forcing cones and chamber length was correct for the period. As I remember it, the gun did not seem to have been futzed with but I was leery of it and did not buy.
We never came up with a reasonable explanation for it, though.
Best,
John

You know if you have a felt wad, 10 gauge shell and 12 bore it will work just fine. Might have been ordered by a live bird or hunter with very special ideas about what would shoot a real tight pattern. Bore diamaters are all over the place on doubles. Add honing to get out pits and you never know what they started out as in the first place. There was also the chambering that was for what we think of as non standard shells before they became a standard size.

I wonder how well the gun patterns with felt wadding and lead shot? I have seen some real strange combos in my travels. Two rear beads, one rear, one middle and one front bead on the same gun. You never know. 10/12?

I have an old W Richards side lever opener which is chambered for 12ga & has the bores marked 14. It was built prior to chamber marking so does not have the nominal chamber marked. Bores now measure just under 13ga, so have no real idea as to just what they were when new. Proofs are Birmingham as best as I can tell, could be counterfeit.

I have owned several 10ga's.

The tightest bores were on an English hammergun. As I remember they were .755". I had the wall thickness measured when I bought it but didn't get around to measuring the bores until I borrowed a friends bore gauge. Shot plenty of felt and plastic wad loads through it before I knew the bore diameters and did the same afterword.

I assume the current owner is doing the same.

Pitted 12ga chambers reamed to 10ga?

Just my shot in the dark.

Best,
Mark

I had a 12 gauge Crescent that had cylinder barrels at .701/.702. I figure that they’d just made the pass to cut the barrels to choke size and then forget (maybe went to lunch or it was a shift change) to bore out the rest of the barrels to .729. That’s my guess and I’m sticking to it!
Steve

Once had a Clark & Sneider (Baltimore@1885) 10 Ga Hammer gun
Bores were .729. Mirror Bores as the gun was in excellent conition. I have no doubht this gun's condition was original
and unaltered.
Reguards
Bill Mcphail