20 ga chamber strength

Posted by MIKE FISHER on April 6, 2018, 9:08 am
65.129.45.87

If you could find a pre-1936 20 ga. marked with 2 3/4" chambers, i.e. a factory special order, would it be safe to use modern ammo in it? I'm mostly finding 2 1/2" guns, some (00) with admonitions to only shoot RST lite loads. Very much want to become an LC owner, but am already shooting several new and vintage SxS's of different gauges and not sure I'm willing to add yet one more loading to an already crowded ammo shelf. Thanks. Mike

Re: 20 ga chamber strength

Posted by Drew Hause on April 6, 2018, 10:49 am, in reply to "20 ga chamber strength"
70.176.142.229

Turn-of-the-century 20g loads with 7/8 oz. and 2 1/2 Dr. Eq. BULK Smokeless ran 8000-9000 psi; DENSE Smokeless was about 11,000 psi. Hunter Arms proved 20g guns with 5.74 Drams black powder with 1.5 oz. shot = about 16,000 psi by modern piezo transducer measurement. ANY vintage barrel should be evaluated before use, but the original barrel was certainly designed for modern load pressures. More information https://docs.google.com/document/d/1F2sQuPm05IE4VWYYnCkvuXmYEzQoWd_SQgaAfUOZEFU/preview

Re: 20 ga chamber strength

Posted by MIKE FISHER on April 6, 2018, 11:05 am, in reply to "Re: 20 ga chamber strength"
65.129.45.87

Thanks Drew. Very helpful and much appreciated. Mike

Re: 20 ga chamber strength

Posted by Pastorcharlie on April 7, 2018, 2:12 pm, in reply to "20 ga chamber strength"
71.166.1.95

Mike,some of us have taken these older guns with short chambers and opened them up to 2.750".It works nice to open the cones up also at the same time.You then will be able to shoot ammo available at your local stores.I do all of my 20 ga. and 16 ga. guns this way and they work fine for me. Best of luck and maybe we will see you at "The Southern Side by Side in a couple weeks.Charlie.