More turn-of-the-century pigeon gun dimensions
In Feb. 1898, C.W. Budd received on consignment a Parker $400 AAH Pigeon Gun SN 87449 with 30 Whitworth barrels F/F and 2 7/8 chambers. LOP was 14 and DAH 2 1/4 with a pistol grip stock and no safety. It weighed 7# 12 oz.
April 18, 1908 Thomas S. Dando, Gun Editor
Sporting Life The generally accepted drop of stock in a pigeon gun is from 2 to 2 1/4 inches. If the gun is more crooked, you can not handle it so quickly. This is especially true with fast birds. In England, where the birds are much faster, the guns are straighter yet. You could learn to shoot a straight-stocked gun in two or three afternoons and you would never use a crooked one again.
Parker #150583, a CHE with 32" Acme steel barrels, 2 7/8" chambers, no safety, extra full comb, and Silvers pad was completed for J.H. Anderson August 6, 1909 with a straight grip, DAC 1 7/16, DAH 2 1/4 and LOP 15.
Dr. William A. Bruette,
Guncraft: Guns, Ammunition, Wing & Trap Shooting, 1912 Hints on Trapshooting
https://books.google.com/books?id=5g51K93as84C&pg=PA159&dqA close shooting gun is necessary for trap shooting. It must be heavy enough to handle a larger load than is used in the field, without excessive recoil, for it is not unusual to fire a couple of hundred shots in an afternoon at the traps. A good duck gun will answer all of the requirements of the average trap shooter, as it is usually closely bored and heavy enough to take up the recoil. However, if the gun is to be purchased especially for trap shooting, let it be a twelve gauge, 7 1/2 to 8 pounds in weight, with barrels at least thirty inches long. Some of the best shots use 32 to 34 inches. The stock should be longer than that used in the field, as the gun is placed at the shoulder before the word to pull is given, and also straighter, for the clay target usually is rising when fired at. The drop of stock used by trap shooters varies from 1 3/8 to 1 5/8 at the comb and 2 to 2 3/4 inches at the heel, the length of arm depending upon the arms of the shooter.
Trap shooters, even those with thick faces, are partial to stocks thicker and fuller in the comb than those used in the field.
In the field a man shoots with his head more or less erect, but the trap shot glues his face close to his stock, and the latter should be of such size and contour that when the shooter's cheek is resting firmly on the stock his eye is looking straight down the barrel. His cheek tells him that his eye is looking right and he swings his gun into place with his right hand, for the hand without conscious thought will always follow the eye.
Therefore, to recapitulate, the gun for trap shooting should weigh from 7 1/2 to 8 pounds, be of twelve gauge, full choke, with a straighter and longer stock and a fuller comb than that ordinarily used for field shooting.
