doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Options for shells in 2 1/2" chamber guns

Here's some low pressure 12 gauge loads for vintage guns published by NSSA. They are silent as to hull length, I assume 2 3/4", but if 2.5" hulls are what you want, they could be used with 2.5" hulls by roll crimping or a Hartin crimp on a press.
https://www.nssa-nsca.org/wp-content/uploads/2011/10/ceretto.pdf

Note that I said " . . . NEED to use sub-7K psi loads . . . " Pressure isn't directly related to recoil, so you aren't going to reduce recoil by reducing pressure (unless you also reduce velocity and/or shot charge). The danger from pressure is either catastrophic failure (blown barrel, cracked frame, etc) or maybe, over a long period of time, causing the gun to shoot loose sooner than it would with lower pressure loads. But please identify for me, with reference to proof or service pressure standards, any gun in which a load developing 7K psi isn't well under its service pressure limit. I note that a 7,000 psi load is already almost 4,000 psi under the service pressure standard for CIP "standard proof" shotguns. Drew Hause has pointed out, with reference to contemporary data, that vintage guns didn't have service pressure limits significantly lower than modern guns--which means that 7,000 psi already provides a very significant "safety cushion". Looking for a lower pressure load to give you even more of a safety cushion, you might well end up with a load that's not as satisfactory as the one you've been using.

In summary:
1. The "standard" U.S. turn-of-the-century 16 gauge load was 2 1/2 dram Bulk Smokeless with 1 oz. shot; "standard" British was 2 3/4 dram.
2. Service Pressure for 16g 1 oz. 2 1/2 Dr. Eq. (1165 fps) BULK Smokeless was about 7000 psi; 2 3/4 Dr. Eq. (1220 fps) Bulk Smokeless about 8500 psi. The gun was likely PROVED at 13,000 - 14,500 psi.
3. Only in the last few years did shell makers provide fps rather than expecting the shooter to translate Dr. Eq.
4. Few shell makers willingly provide the pressure of the load.
5. It was easier for clubhouse experts to simply say "use low pressure loads in your vintage double".
6. Desiring lower RECOIL is reasonable with 100 year old wood and lock up. And lower shot weight and lower fps = lower recoil and usually also = lower pressure.
7. With adequate wall thickness (and we now have no excuse for not knowing the wall thickness from breech to muzzle) there is no rationale for advocating "low pressure" loads; we should suggest "loads for which the gun was designed".
8. I shot 2 rounds of low gun recreational skeet at Ben Avery this morning with my 1906 16g Damascus OE. I know the right barrel wall thickness to be borderline. I therefore chose to use 2 1/2" RST 3/4 oz. at 1100 fps loads with a pressure of 4,600 psi, and have a steel and leather hand guard at the thin area. I also know the barrels previously survived 250 2 1/2� 7/8 oz. Polywad Spred-R shells and 100 2 1/2� 7/8 oz. at 1145 fps. (about 8000 psi) loads without dimensional change, so I'm not too worried.

BTW with the winter rains the desert is a riot of yellow and gold

Skeettx said he was looking for lighter 7/8 ounce loads. Fiocchi makes a "trainer" 12 gauge 2-3/4" load that is 7/8 ounce of shot (7-1/2 or 8) at 1200 FPS. According to the distributor in the US they are between 6500 and 7500 psi. I called them twice before they would tell me the pressure range. These are not as cheap as Herters or Estates. I have used them a lot in a 12 ga damascus gun with 2-5/8" chambers and long forcing cones, and other 12 gauges.

Another possibility for 2-1/2" fans is at William Larkin Moore. They have custom loads made and sell them in 7/8 ounce 16 and 20 gauge. I have used them in #7 and #7-1/2". WM Larkin Moore's shop is in Scottsdale, AZ. I think they are about $10 a box.

About shooting in cold weather. My experience in Alaska is that ALL loads, including factory, lose energy and shoot dirtier when temperatures fall much below 40 degrees. I don't shoot when it gets into the single digit temps or lower, but there are clay shooter leagues here that shoot at 12 below zero! Many of these folks handload. I generally avoid shooting loads down below 5000 psi in the depths of winter.

Prior to 1924, the Belgian and British Service (using) maximum load for 12g 2 1/2� and 2 5/8� shells was 1 1/4 oz. / 3 1/4 Dram Eq. (1220 fps). The pressure of that load would have been about 8500 psi with BULK smokeless powder; with DENSE smokeless 9,500 - 10,500 psi.
The standard 2 1/2� shells were usually loaded with 1 1/8 oz. shot and 3 Dr. Eq. of BULK Smokeless with a pressure of 6500 - 7500 psi; DENSE Smokeless was 9000 - 10,000 psi.

A lot of the older reloading manuals will note that the lower pressure formulas they provide are not good cold weather loads. I don't know what the low noise-low recoil factory loads generate for pressure, but I do know that I've heard very "poofy" reports (not just less noise) on days when it's freezing or a little below.