[rbernie]

If I can drop a 3" shell into a smoothbore chamber (stopping on the rim) on a barrel marked as 2 3/4", should I presume that somebody re-cut the chamber? Or are shotgun chambers cut long (compared to a rifle/handgun chamber) since they headspace on the rim and aren't rifled?

[Milkmaster]

I beleive sir that the chamber is sized for the entire length of the shell AFTER it has been fired. The crimped portion of the shell folds out into the remainder of the space. A 3" shell will fit in one marked for 2 3/4", but not have any room when fired therefore creating additional pressures. Take serious heed to what ammo the barrel specifies in any firearm. The info is there for good reason! Please be careful.

[ArmedBear]

I beleive sir that the chamber is sized for the entire length of the shell AFTER it has been fired.

Note that a 2 3/4" shell is 2 1/4" long when crimped, and the hull is about 2 3/4" long after it's been fired. Milkmaster is correct.

[mnrivrat]

Just in case you needed a third opinion !

The chamber needs to be long enough to not only chamber the unfired round, but to chamber the fired round wich includes the crimped end. A 3 inch shell will load into and fire from a 2&3/4 inch chamber - it will not have room for the crimped end to expand outward and therefore will creat an obstruction in the forcing cone area which will significantly increase the chamber pressure .

[rbernie]

I beleive sir that the chamber is sized for the entire length of the shell AFTER it has been fired. The crimped portion of the shell folds out into the remainder of the space. Excellent - that was my suspicion. Thanks much. :)

[Afy]

Use a paper cartridge.. with one that doesnt have a crimp. Old world S&B or Kynoch

[ArmedBear]

Are there 3" paper cartridges?

[Hornet 6]

Even roll turn over shells are longer once fired.
If it says 2 3/4" it almost certainly still is.

Neil. :)

[Flintlock Tom]

Along those same lines, I am looking at reloadable brass shotgun shells. Since they don't have a crimped front end does it matter how long they are as long as they are shorter than the chamber length?
My chamber length is 2 3/4", the shells are 2.4". Will those work?

[HuntAndFish]

I think they will, but the shot pattern will suffer. Similar to shooting 2 3/4 inch shells out of a 3 inch chamber. The transition of the wad into the barrel should be smooth for the best shot pattern. That happens when the crimp unfolds and matches the end of the chamber.