20 gauge chamber length

[Bill Murphy]

The long and the short of it is that these are shotguns, fired at low pressures, from thick barrels. It just doesn't matter how long the shells or the chambers are, as long as the shells are not overloaded, everything will be fine, the pheasants will be dead and the guns will not blow up. I think Dr. Drew and others have clarified that in past research.

[Drew Hause]

Scott: please help us understand your question.

Scroll down about 1/3 here and there are several references to shell and chamber length
https://docs.google.com/document/d/1...vwLYc-kGA/edit

“Mr. Griffith on Shotgun Patterns”, 1897
https://books.google.com/books?id=inQCAAAAYAAJ&pg=PA234
Studied “Turnover” – case longer than the chamber in reference to vintage roll-crimped shells

Charles Askins “The Cone” Field & Stream, Nov. 1921
https://books.google.com/books?id=UP...J&pg=PA700&lpg
W.A. King for Parker Bros.
Referring to the cone, we ordinarily permit our shells to lap into it 1/8-inch, but as a matter of fact we have found that the majority of guns will shoot a better pattern with even more lap than this. In fact, we can secure extra good patterns by shooting extra long shells, permitting the lap to extent to the point where we begin to tear off the ends of the paper. At that point we do not seek to give more lap. In user’s hands we do not advocate the use of longer shells than those which give 1/8 lap.

Everything in the shotshell world changed when Remington introduced the ‘SP’ high density polyethylene compression formed hull with a separate base wad in 1960, followed by the polyethylene ‘Power Piston’ wad in 1966.
Winchester/Western introduced the Mark 5 polyethylene shot collar in 1961, followed by the one piece compression formed plastic hull for the Super-X in 1964 and AA Target shells in 1965.
The Federal Riefenhauser (straight wall) ribbed plastic shotshell was introduced in 1965.

Many modern 2 3/4" plastic hulls are indeed a bit shorter than 2 3/4" after firing; the box is still labeled 2 3/4".



I think there are good reasons to not use 2 3/4" loads in a 20g with 2 3/8" chambers.
2 3/4" 12 g loads are of no concern in 2 5/8" chambers.

[Bruce Day]

Originally Posted by Bill Murphy

The long and the short of it is that these are shotguns, fired at low pressures, from thick barrels. It just doesn't matter how long the shells or the chambers are, as long as the shells are not overloaded, everything will be fine, the pheasants will be dead and the guns will not blow up. I think Dr. Drew and others have clarified that in past research.

Dead on right. How many times has this same matter come up ? Over and over and somebody must feel that their gun is so infirm that it will blow up if the slightest miscalculation is made . Enough, enough.