I'm not sure what I'm looking at here - 21.5" double barrel hammer gun marked "F Williams" on the lockplates, "Laminated Steel" on the rib. Has the vibe of a very old bar gun?





10 gauge shells fit, but you can see the '12' markings.





Pre-existing related threads for easy reference

F. Williams shotgun value?? (pics included)
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=199311&page=1

Fred Williams English Maker
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=174888&Searchpage=1&Main=15884&Words=%22F.+Williams%22&Search=true#Post174888

Looks like a sass gun

This works and I doubt if this F. Williams was the maker
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=174888

Looks to be 1868-1875



"Laminated Steel" on lower quality guns usually means Twist
I agree the barrels were almost surely cut.
If the chamber was bored out to 10g and barrels honed, careful measurement of the wall thickness from breech to muzzle, by an expert, is required. Please let us know the chamber and bore dimensions.

Thanks for the responses, gentlemen. Agreed that this seems like it's second life was as a "Street Howitzer" but i think it's fighting days are over. Bore is a bit rough.


If the chamber was bored out to 10g and barrels honed, careful measurement of the wall thickness from breech to muzzle, by an expert, is required. Please let us know the chamber and bore dimensions.

I'll dig out the digital calipers and circle back, first chance.

Short chamber 10 bores are not much in demand. Ammo is rarely seen today, making it even more a cult gauge than the 16 or 28 has become. As it is described it is a decorative item only. It is tired, been used and abused and does not need anymore stress. If it could talk you would feel the certain need to buy it a drink or can of oil for its troubled past. At least they have not polished it up all shinny and chrome like.

The same situation exists for all old shotguns with with 2-1/2" chambers, but doesn't put people off them. There are about as many shells available commercially for 2-7/8" 10's as 2-1/2" 12's (meaning around none). Reload and enjoy, if the gun is safe. I have 5 or 6 and they are some of the most enjoyable guns I shoot. Not really that much more effective than a 12 with low pressure loads, but fun.

My local gun shop has multiple cases of 2 1/2” 12 shells right now. He was buying what he could to sell and came across a large number of 2 1/2” shells being imported from Spain I think. I have not seen a new factory short ten in 50 years I bet. There are some still around but not many. Most short ten users cut down those Roman candles and load their own. Most I know limit it to 1 1/8 or 1 1/4 ounce loads. At one time a short ten was a well thought of long range duck gun on the Eastern Shore. My grandfather had one which he used for all his ducks and geese hunting.

Barrel measurements, metric -

Muzzle OD - 22.58
Muzzle ID - 19.28
Breach OD - 33.38
Breach ID - 21.75

Winchester Brass Shells trimmer to 65, loaded specifically for this piece by a Vintager friend of mine -

Case rim - 22.25
Case base 21.57

So your bore is .760 based on the muzzle measurements. A 10 bore has a .775 bore as a standard so your is slightly tighter. Often 10 we’re bored to 11 bore diameter and 12’s to 13 bore. Your might have always been a 10 with a bore that was 12 which is now bigger because it got cleaned up several times to remove pitting.

I had a hammer gun that was proved as a 12, at .729 presumably, that had been hogged out to .783. The weird thing was that it was really clean looking on the outside and even had a little case color left.

Chamber entrance of .856" is the 10 gauge standard.
.760" bore would have been marked 11/1 at the time of proof.

Well, 21.75/25.4 (metric) works out to .856.

As for the muzzle inner diameter, remember that's at street howitzer length. Who knows how tight it was when it left the factory full length (whatever that may have been).

Chambered 10 gauge choked 12 gauge is something I've never heard of before [ETA; .690 is normal 12 gauge full choke - had to look that one up]