doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Conversion - SxS Hammer gun to Cap or Flint ML ??

You're 3 and 0 in this thread...3 posts and zero contribution.

My guns(Baker's) have 2 5/8" chambers. I cut the hull down to 2 5/8" and reload with a modern reloader (Mec Jr. and a Mec Grabber) that uses the star crimp. The thing you need to do, is close the "hole" in the center of the star crimp, since you have now cut the hull shorter. To do that, just install and over shot card, before crimping and the hole is closed. This type of over shot card and crimp is called a Hartin crimp.

There has been discussions before about shooting 2 3/4" shells in a 2 5/8" chamber. I wish I could remember who did the testing, but maybe a search would find it for you. Anyhow, the rise in pressure was pretty minor and it appeared to not be a problem. But, I still cut my hulls and reload them at 2 5/8" so that way I KNOW they are low pressure and a high pressure didn't get slipped in somehow.

I currently have 1000's loaded and always looking for an excuse to shoot them.

Boy Roundaball, you are quicker than most. That is why he is HomelessjOe.

Why don't you just pour a chamber cast?

Based on the findings above I don't see any reason to.
The objective was simply to determine if 2&3/4" standard shells can safely be used...a Go/No-Go decision...given the above findings do you think a cast would produce a surprise game-changer decision?

Congrats on finding and recognizing a treasure. Many such have been trashed out of ignorance. My compliments on your enlightenment.

Bell ran the pressure tests alluded to above and reported in a series called "Finding Out For Myself" in DGJ. He pretty well "popped" the myth of differing time-pressure curves and low pressure for BP. Low pressure nitro in 2 3/4" cases is fine for most vintage applications.

For convenience, I'd suggest you load any of the 2 3/4" loads in any of the standard manuals for sub 7500 psi, 7/8 oz shot, and sub 1200 fps. Low pressure for the metal and low recoil for the wood and the shooter. I happen to have a good supply of PB, so it is what I use.

BP and short cases are fine for authenticity. If that trips your trigger, have at it. Consider brass cases while your are on this route, too. If, however, you find yourself with limited time to reload, consider the nitro route. Just be sure you know what you are feeding the 'ole hoss --- every time.

BP is all I've used for years now...was thinking of something like a "3 & 1" field load...ie: 80grns Goex 2F & 1oz shot for 1000-1100fps range...have some Circle Fly 1/2" and 1/8" wads on the way...play with the wads, see how it patterns, try some trap targets, etc

I don't know about American gun makers who "purposely cut" short chambers, but it is a documented fact in the sporting press of the day that certain well-known trap shooters around the turn of the last century used over-long paper shells so that the shot was buffered by nipping-off the mouth of the shell, which supposedly reduced shot distortion in the forcing cone. Some of the ammo makers told their hired pros to stop doing this 3-inch-in-a-2 5/8-inch-chamber trick because they were supposed to be demonstrating ammo available to the common man. Based on personal experience, those guns with over-long shells must have really kicked...unless the forcing cone was enlarged consistent with an over-bore to, say, .740-inch, which was typical for some live bird guns I have inspected.

When discussing 2 5/8-inch versus 2 3/4-inch chambers we need to take the star crimp shell into account; it wasn't "invented" or more correctly put into service until 1939, at a time when thick paper shells were endemic. Latter-day thin-plastic shells in guns made for thick-paper shells have some leeway in the forcing cone...UNLESS you bought Bismuth waterfowl loads several years ago when Destry and I were duck hunting in Louisiana pre-Katrina:

I was testing Kent's Tungsten Matrix for the company (and for an article), as compared to Bismuth in factory loaded Eley and Winchester shells. My old GH Parker almost knocked me out of the blind, doubling, and locking shut! I was able to remove the fore-end and thus break the gun open without the extractors pushing up the shells (the reason it wouldn't open was the swelled shells resisting the extractors). I cut a stick for a ram rod from the blind and managed to pound out the fired Eley shells, which when compared to our other fired shells (Winchester Bismuth and Kent TM) seemed over-long. I stopped using the Bismuth/Eley, but saved the fired shells and did some measurements at home:

The fired (doubled) and failed Bismuth/Eley were shredded and stretched at the mouth, with loss of substantial chunks of material. I opened unfired Bismuth/Eley shells and they were a full 3-inches! The box said 2 3/4-inch! The fired Bismuth/Eley shells, when measured from the base to what remained at the mouth, were 3- to 3 1/8-inch (stretched!); the fired Winchester/Bismuth and Kent TM were right on 2 3/4-inch. My Parker GH was made in 1927, twelve years before guns would have been chambered for 2 3/4-inch paper Star Crimp shells, which didn't exist till 1939.

When you consider how few of the guns we talk about on this DoubleGun website were made in the post-1939 era of paper Star Crimp shells (much less the latter-day plastic), the 2 5/8-inch versus 2 3/4-inch analysis is like paper-apples and plastic-oranges. Based on my experience with the mis-marked 3-inch Bismuth/Eley in a 2 3/4-inch box (the shells themselves were marked 2 3/4-inch!), I'd say that using 3-inch shells in a 2 5/8- or 2 3/4-inch chambered gun is a no-no. As to today's 2 3/4-inch Star Crimp plastic in Parkers and other pre-1939 shotguns chambered for the then endemic paper roll crimp loads, I'd say that the idea of reaming out supposed 2 5/8-inch chambers to 2 3/4-inch has been debunked by S. Bell/T. Armbrust et al, and I should mention Babe DelGrego:

I was doing an article about this for the DGJ and Lawrence used the Parker factory reamers on my AAH Pigeon Gun; virtually zero metal was removed. In the final analysis, much of this measuring of chambers is philosophical; time might be better spent analyzing how many angles can dance on the pin-head of HomelessJoe (who is now batting Zero for Four in the non-contribution meaningless-quip department). EDM

I'm just trying to save the Colts life.


Rocketman...I take it you missed this part.

It is noted that immediately after the introduction of the fold crimp shell in Great Britian there was concern the nominal 2½" (in reality about 2 9/16") shell was so short it would be mistaken for a 2" one. Tests were begun immediately upon putting the normal load uo in a fold crimped 2 3/4" hull which resulted in a shell having about the same identical "Loaded" length. Results all appeared positive & this work was completed very shortly following WWII. These tests were conducted by the British Ammunition makers who had the knowledge & equipment to fully test. This was fully reported on by Burrard in "The Modern Shotgun". These tests were conducted using "Thick Paper" hulls in standard chambers with standard forcing cones. The conclusion was as long as there was clearance between the end of the loaded shell & cone for the crimp to start to open in a normal manner & the load was suitable for the gun there was little concern about the lapping of the fired hull into the cone. I do believe that virtually all British shells from that day to this marked for use in 2½" chambers & which are closed with a fold crimp have been longer than the chamber in which they were to be fired. Work in this field later than the 1940's have simply been a re-invention of the wheel. It would not of course be recommended to fire a shell longer than the chamber in a gun having a "Stepped chamber in which the crimp would actually open up into the bore itself or a shell long enough to actually have the crimped end squeezed into the cone prior to firing. This gives the effect of an overly strong crimp. Along this line it was "Not" recommended to fire 2 3/4" Roll Crimp shells in the shorter chamber, only the fold crimp ones. Roll crimped 12ga 2 3/4" shells were available well back into the 1800's. Many American 12ga doubles were ordered with 2 3/4" chambering & according to Hunter Arms Drawings they were standard on their 12ga guns at least as early as 1907. Several of my Lefever 12's have 2 3/4" chambers which I have no reason to believe are not original & I have both a 10ga & a 16ga with 3" chambers. Shells for both these gauges were available in 3" length when the guns were built, but never became standard in either & became increasingly harder to find as time went on. There is "Absolutely No" reason to believe either of these are a later re-chambering.