doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Chas. Osborne 14b/12ga hammergun

Seeking some insight into a wonderful hammergun now on hand.

Chas. Osborne London No. 2841 on top rib
29 7/8" damascus barrel stamped 14b
Chambers are now 3" 12ga
Bores .736"
Chokes .018" and .024"
MWT .040"
Barrel alone weighs 5lbs 5oz.
Ornate high rebounding hammers
"H. Walker's 1756 Patent" present on water table
Capped pistol grip
Very ornate horn forend tip with patented forend lever release

A 12ga shell is the slightest amount of wiggle when in the chambers, but the rim cuts are spot on. As heavy as the barrel is, and with it being stamped 14b, my assumption is that it was intended for some heavy shooting at the time made , and then adjusted to be a long chambered 12ga.

Pictures: https://drive.google.com/drive/u/1/folders/1zTGzP4mUAUBPJjJL9oJyKwNn7hmKhHmC

Appreciate feedback from those who've encourtered similar. Likely won't keep it, but would think it find to shoot with 12ga low pressure. Again, this barrel is a damn tank.

Thank you.

I haven't seen this exact situation, but have seen a lot of rebored/rechambered guns. It was likely a 14 bore gun that was rechambered and rebored. I don't know that the statement about a 14 bore with heavy barrels being intended for heavy shooting rings true of an English shotgun. A 14 bore was not up to a 12 in power and had a smaller bore. Not a gun in that time that would be built or chosen for heavy shooting of waterfowl etc. That would have been a 10 or 8. Typically reboreing and English shotgun is generally not practical as they tend to have very light barrels compared to other manufacturers. Also, the bores as rebored are pretty large for a 12 bore, especially of that period. I will throw out a guess. It was originally a 14 bore rifle and was rebored to the smallest ID that cleaned up the rifle barrel. That would explain the heavy barrels and the overbored size. It was a common practice over the years to take rifles with ruined barrels and convert them to shotguns. Very common with rook rifles to .410 or 28 ga, and I have seem quite a few large bore doubles bored to 20 ga etc.

Charles Henry Osborn information is here Bill
https://doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=428703

The proof marks you posted date to 1868 - 1875. Apparently there is no record of DOM by SN for Osborne guns.
14 bore would be .693", but up to .709" would be marked 14 (fractions were not used until 1887)
The gun had to have been reproved after the chamber and barrel modification. Are there no proof marks on the barrel flats?

A 14b double rifle
https://www.gunsinternational.com/g...-safari--69-cal-sxs.cfm?gun_id=101217624

There are no proof marks on the flats, Drew. There are two other markings on the short rib being G D, and possible an A or L.

Thanks Bill. That very much suggests the conversion was done in the U.S.