Choke regulation today is basically a mathematical concern. The customer orders his gun with a set constriction of chokes, or has a set of multi-chokes provided. These are made to pre-determined dimensions.
The customer then buys whatever loads he prefers or can access and assumes the performance is what he wants. Very few ever pattern test their guns to find out.
This 'Special Quality' Bonehill 'Belmont' boxlock reminds us of the careful regulation that gunmakers used to perform on shotguns before delivering them to customers. Remember, this is a C.G. Bonehill, not a Purdey! Even middle tier Birmingham gunmakers could and did offer this service and sportsment took the business of load and regulation seriously.
Unlike today, where a customer might order a gun with 1/2 choke in the right barrel and 3/4 choke in the left, it was then normal for him to specify the pattern he expected the gun to deliver from each barrel at a given distance, using a specified load of powder and shot.
The specification here is that the right barrel deliver 132 pellets from a 1 1/8oz load into a thirty inch circle at forty yards. The left was required to deliver 168 pellets into the same 'killing circle' at the same distance.
Choke constrictions do not perform the same when the cartridges change. This customer knew what cartridges he liked to use and knew what he wanted his gun to deliver at forty yards when he used them. No guess work involved.
To achieve these results, the gunmaker tasked his regulator to go to teh shooting ground and start test-firing the gun. He would then adjust the chokes by honing and polishing until the results were as desired. It was a skilled, time-consuming job and more of an art than a science.
The level of detail specified on the label, so that the owner could repeat the test results, is impressive. The regulator specifies 42 grains of Schultze (smokeless) powder or suggests a black powder alternative of 3 drams of Curtis & Harvey's 'Diamond Grain No.4'. Note also, the detail about wad thickness and card placement, as well as the specification of 1 1/8oz of No.6 Newcastle Chilled shot.
Bonehill's 'Belmont Interchangeable' was an early machine-made gun which was often hand-finished to a surprisingly high standard. This example is superb. Bonehill is one of those, now obscure, makers whose best work is wonderful.
While many of the guns the firm made were middle and lower grade boxlocks and hammer guns, it is worth paying attention to each and every gun encountered, as the best of them are beautifully made and incredible value in today's market.
We can see from the attention that went into the regulating of this 12-bore, that the firm was capable and serious about gunmaking.
Published by Vintage Guns Ltd on (modified )