Dave, you know me better than that. My PH Twist gun letters as 3 1/2". While you are researching the beginning of the Super X 3 1/2" ten gauge ammunition, I will dig out the date of the #6 frame PH manufacture and verify the chamber length. If it says 3 1/2", and if we are skeptical, maybe Chuck Bishop will confirm. I will post the serial number.

The earliest listing I have for the 3 1/2 inch Magnum 10-gauge Super-X shell is in the April 1, 1932, Western Ammunition for Rifle, Revolver and Shotgun. It is not in July 1, 1931 or February 1932 Western paper. The Ithaca NID Magnum-10 first appears in the second 1932 Ithaca Gun Co. catalog. Remington didn't add a 10-gauge 3 1/2 inch Magnum shell to their offerings until their January 13, 1937, price lists. Peters didn't list a 3 1/2 inch Magnum 10-gauge load until their January 3, 1950, price lists.

You could special order a 10 gauge very early on with 3 1/2” chambers as well as special order the brass shells for it. Do we know the earliest 10 gauge documented with 3 1/2” chambers?

Serial number of my #6 frame PH is 118,498. Chuck sent me a letter indicating the 3 1/2" chamber. I'm sure he would confirm his research. It is a 1903 gun ordered by Iver Johnson, apparently, certainly, before the Western Super X 2 ounce loads. Dave has posted interesting information.

Parker Brothers posted maximum loads for their smallbore guns in the popular "Small Bore" pamphlet which were lighter than loads specified in orders for guns in the 1912-1918 era, which were 1 ounce loads. I have owned guns, 20 gauge 3" chamber guns, that were specified to shoot 1 ounce loads when PB didn't admit that they approved of such loads. They were #2 frame 20 gauges, but maybe some smaller frame guns were specified for 1 ounce loads, I don't know. Discussion continues.

Has Dave "Researcher" lettered the #2 frame 20 gauge barrels I sold to him many years ago to find out the construction of that original gun?

L.C. Smith used three frame sizes for 10ga guns during the Syracuse era according to David Williamson. Very similar to Parker. L.C. smith did not number the frame sizes but measurements across the breech balls have confirmed it. After the move to Fulton all 10's were built on the same frame.
With Parker TL hammer 10's if you wanted a 8.5lbs to 9lbs gun with 30 to 32 " bbls you got a 3 frame, if you wanted a 10lbs gun with 30 to 32" bbls you got a 4 frame, if you wanted a 10lbs plus gun with barrels over 32" you got a 5 or 6 frame gun. Just my observations but there are always exceptions.

Craig sends us some interesting information, but his observation about frame sizes larger than #4 in hammer guns is a bit incorrect. Hammer guns of ten gauge in frame sizes larger than #4 are rare, #5 almost nonexistent except in very early eight gauge. In sixty some years of collecting, I have never seen a #7 frame hemmer ten gauge. I would like to see one. #7 frame hammer eight gauges are the most often seen.

Bill: I value your input and knowledge when it comes to large frame Parkers and agree that 4 and 5 frame TL hammer guns in 10ga are rare. 26498 a B TL hammer is the pinnacle of the big tens, displayed by Mr. L at last year's annual meeting people's choice award.

I had one years ago because I had thought of sending the Zephyr to Briley for chokes and needed to measure the muzzle diameter to determine for thin walls or regular chokes .

I have seen English ammo catalogs that predate the 10 ga 3.5" Super X of the 1930s . They were 1900s or 1890s catalogs that listed the 10 ga from any length up to 3.5" . Actually They may have listed one longer than that .
I dont doubt that a #3 frame Parkers could handle it . The CG Bonehill I owned had 3.5" chambers though I only shot RST 2 7/8s out of it . The guy I sold it to ran alot of 3.5" shells and never had a problem. That was a heavy barreled gun to start with .