doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Longer shells in Short Chambers

Looking for some help with this. I have always thought that it is inadvisable to load 2&3/4" shells in guns with chambers shorter than 2&3/4". I know that the longer shells will chamber, but I understood that the problem is when the shell is fired and the crimped part of the shell is opening in the forcing cone part of the barrel. my second part of the question is whether you can safely reload 2&3/4" shells to lower pressures that are required in older firearms with shorter chambers.

I don't think any of this is a good idea, but I am hoping for some technical support on this from many of you that know much more than I do about safe reloads,chamber lengths, etc.

Thanks,

Ed Pirie
West Topsham, Vermont

This comes up so often we've got a permanent thread (much of which has been 'borrowed' from Researcher and PCGA forum) over on 16ga.com:
http://www.16ga.com/forum/viewtopic.php?t=1694
http://www.16ga.com/forum/viewtopic.php?t=1751
AND the Low Pressure Reloading group over there has all the infro you'd want.

Ed, what revdocdrew led you to is good advise. Some people say it is alright to shoot 2 3/4" shells out of shorter chambers, but I believe in older guns the shell doesn't open all the way like you said and you could develop higher pressures than normal. In the web silte that he listed you will get lower pressure reloads, down to 4400 psi, which is great for the right chambered gun.
You can also still buy 2 1/2" shells by a few companies, mostly English, like Gamebore.
So I would stick to the shorter shells instead of low pressure shells in 2 3/4" length. IMO David

Ed, The site that revdocdrew led you to is good advise. Some people say it is alright to shoot 2 3/4" shells out of shorter chambers, but I believe in older guns the shell doesn't open all the way like you said and you could develop higher pressures than normal. In the web site that he listed you will get lower pressure reloads, down to 4400 psi, which is great for the right chambered gun.
You can also still buy 2 1/2" shells by a few companies, mostly English, like Gamebore.
So I would stick to the shorter shells instead of low pressure shells in 2 3/4" length. IMO David

Ed,
I'm shooting 2 3/4" paper shells in my 2 9/16" chambered Parker and Ithaca guns. I also have a 2 9/16" chambered single shot with a pressure measurement device on which I checked pressures my load. I believe the Double Gun Journal article by Sherman Bell covered the issue on a 12ga pressure gun in which they cut a 2 1/2" short forcing cone chamber and measured pressures. My recollection was that they got from zero to +15% increase in pressures as compared to a modern chamber. I've seen at least this variation in pressure from loading manuals on recipes.

Another reason I don't worry about shooting 2 3/4" shells in my 20 ga Fox (whatever the chamber length is) is that modern plastic hulls are much thinner than the old paper hulls. I just measured a AA, an STS, and a Federal. All miked in at about 0.017". That's not a lot of constriction, even IF the mouth doesn't fully open because of the shorter chamber. Maybe someone can measure the thickness of some new or once fired paper huls for comparison.

Ed, of the few issues of DGJ I have, the Winter 2001 one has in it one of the articles by Sherman Bell called "Finding Out for Myself" Part V "Long Shells in Short Chambers".

After extensive testing carried out in a very professional manner he concludes:

"With loads that are sensible in a light 21/2 inch gun, we see no dangerous pressure levels produced. I see no reason, related to safety, to modify an original 2 1/2 inch chambered gun to shoot 2 3/4 shells, If The 2 3/4 Inch Load You Intend To Use Would Develop Pressure That Is Safe In That Gun, When Fired In A Standard Chamber!

I once had the gall to quote said article in the forum you were referred to. I ended up being banned from it after some interchange with pontificating "expert" posters there whose philosophy is of the type: " my mind is made up, do not confuse me with the facts." Apparently they are no longer lurking there.

JC(AL)

I would only repeat that pressure and recoil are not necessarily the same thing and it would seem reasonable to avoid increasing recoil when shooting a SxS that may have greater than 75 year old wood. I can testify that recoil with 2 3/4" AA 20g target loads is WICKED in my 1922 Trojan with chambers that measure closer to 2 3/8"

Ed You'll hear what Chuck H. said from many of us and its not limited to the 16 gauge, but, FWIW, in the 1960s and not knowing much about this alleged "problem", I fired thousands of standard factory 16 gauge 2 3/4" loads thru an A.H. Fox 16. Verdict - no problem, whatsoever. At the same time, my pop did the same in his Parker. Verdict - no problem, whatsoever.

The article that JayCee notes would make you feel much better, in my opinion - well worth the bucks to get the results of some thoughtful testing and measurement taking.

Best of luck.

My 1911, 20 gauge VH Parker with 2 1/2" chambers,
digests AAs with ease and handles standard 1 oz field loads just fine but due to it's six pound weight, is unpleasant to shoot large quantities of the latter. I do not hesitate to use the 2 3/4" standard 2 1/2 dr eq, 1 oz field load in it for the infrequent shot at grouse.
90 years of such abuse. Will she stand another 25 (If I'm lucky)? Stay tuned!