I was wondering if anyone on this forum is familiar with english 11 bores? Just received in the mail my Jas king London 11 bore and was looking for any info on the peice thanks A.J.

I've seen 12 bores proofed as 11s or big 11s, but never a gun that's was made for an 11-gauge shell.

What do the proof marks look like?

OWD

Well its marked on both barrels with and 11... A standard 12 gauge round is to small and a Brass ten gauge american round is far to big... I know English 10 bore round are a bit smaller but this is quite a bit smaller.. The proofs are a crown.. and something under it I will post some pictures tommorow.. thanks again A.J.

A brass Parker 12B should fit if you can find one - the 12B is a true 11 bore.

well this is the start of the initial cleaning, Got a couple pictures of the proofs so u guys can see....

Birmingham Black powder proof marks, Pre 1904,for 11G bore size [Bore diameter should measure between.751 -.762 inches to still be in proof.]Chamber size will determine whether the gun was made as a 12G or a 10 G. Weight of the gun will also be a clue as to its design size.My opinion is that it is likely to be 10G because many guns of this vintage,[pre the introduction of choke boring] were bored one gauge smaller than nominal [ie; many 12G guns of this vintage were bored and proof tested at 13G.], I think that the objective was to improve pattern density.Others have suggested it was a wear allowance to allow for a future reproof of damacus/twist barrels.Recommend that you have a gunsmith measure the chamber size and compare results with the dimensions specified in the relevant rules of proof.

It is definetly a heavy gun 8 1/2 pound range very thick barrels, so, would that make it a ten gauge and if so what type of round would it be?

The "Modern Shot Gun," Vol;3,by Burrard, pages 202-3 details the standard chamber lengths and corresponding loads for 10G black powder cartridges.I would recommend inspection of your gun by a competent gunsmith and his/her confimation that the barrels measure,"In Proof," and that the barrel wall are of a satisfactory thickness,prior to any use.Provided the gun is approved by such an inspection, you may wish to consider using the loading recommended by Burrard for 2 5/8 chambers even if the chamber measures longer than 2 5/8[ Play it safe!].

AS A PRECAUTION ,PLEASE DOUBLE CHECK BURRARDS POWDER CHARGE RECOMMENDATION, HE STATES DRACHMS THIS COULD BE A SERIOUS ERROR AND SHOULD READ DRAMS![SEE GOUGH THOMAS, "GUN BOOK," PAGE 266].

BLACK POWDER USERS, PLEASE COMMENT ON THIS POTENTIAL SAFETY ISSUE?

I have Birmingham underlever that is stamped like yours except it has a 13. It is a 12 bore though.

Merriam Webster's Collegiate Dictionary
Drachm; chiefly Brit Dram
My take; "IF" Gough Thomas would have spent as much time Studying & Learning from Burrard as he did trying his utmost to make him look bad the Whole World would have been the better for it.
The term Drachm is found quite common in older writing in reference to Black Powder & always meant the common Dram, thus no safety factor involved.

On the gauge markings note that prior to 1887 neither the nominal chamber size Nor the in between gauge marks were stamped on a bbl at proof. Thus a bbl stamped 11 had a bore that took a .761" gage to 9" from breech but would not take a .775" gage. This size bore was most often found on gun chamberd 10ga but could be found on a 12ga chambered one, perticularly if all brass sheels were to be used. The proof house had the gages in all the whole numbered gauge sizes & stamped the bbl according to the largest one which would enter the breech to the desired depth. Prior to the general acceptance of choke boring they had been gaged from the muzzle, a hold over from muzzle loading days.