doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com No RST at the Southern this year

Argo, this is what I posted on the topic you referenced.:

“ This subject of shooting 2 3/4” hulls in 2 1/2” chambers is a recurring question on this board. But perhaps it’s not bad to revisit it every once in a while. As mentioned above pressure tests shooting the longer hulls in short chambered guns did not raise pressures significantly, only 500 to 1,000 psi. That’s normally not a significant amount of pressure. And long ago, when American makers still cut chambers 2 5/8” they recommended using 2 3/4” shells. They wanted to hull to open part way into the forcing cone, believing the longer hull would provide a better gas seal than the shorter. Most of my doubles are damascus barreled with short chambers and I only shoot 2 3/4” in all of them. Never a problem. If my 2 3/4” hull mouths are not frayed after firing I am comfortable that the hull mouth remained in the forcing cone and is safe.

However, one word of extreme caution: regardless of hull length be sure the pressures, velocities, and payloads are within the design limits the gun was made for.”

In my misguided youth I had a number of chambers altered to longer for ease of use. No longer. I will either load safe stuff or just not shoot them until I can use safe ammo as they were built for. I agree with your observations and conclusions.

Life was and shall be someday so much easier when you could easily buy powder and primers to reload low pressure loads, or buy them from RST. Just to load a reasonable number of low pressure loads I end up buying a ton of extra different powders which right now are very hard to obtain. I have trimmed all my Remington 20 hulls from 2 9/16 factory length, to 2 1/2" length and they load normally. That gives me a go to hull, for the 20, which is safe in all my guns given reasonable loads. There are a few very low low pressure loads for Remington 20 in the 6400-7700 psi and more that are fairly low pressure in the low 8,000 psi. And I have thousands of them to work with. So once I have figured out what I need to make, it is simply a matter of doing it.

Again, the published length of the factory load is not nearly as important as the pressure it generates to begin with. Much is made over a factory shell being 1/4" longer than the chamber length of older short-chambered doubleguns, but most of them aren't 2 3/4" in length when fired, anyway. Pick up some different brands of fired hulls next time you're at a range. Take them home and measure them. I've never found but one or two loads that opened to a full 2 3/4 inches.

I recently measured several different brands of fired hulls that are sold as 2 3/4", again. None measured that. Most were closer to 2 5/8".

Stan makes an important point, and I always learn best with pictures
Some gun club dumpster diving > 10 years ago so today's shells need to be checked







It has been reported that 16g Fiocchi loads run short

HOWEVER, if the case mouth is feathered, the hull is too long in your gun
67 mm L; 65 mm R

I have never bought special components to load for short chamber or Damascus guns. I can't imagine that you could blow up a good 12 gauge Damascus gun by shooting 7/8 ounce loads at 1150 fps, with common Red Dot.