My understanding is that revolver barrels have a forcing cone that receives the bullet as it exits the cylinder. The portion of a rifle chamber between the mouth of the case and the rifling is the throat. The leade is the portion from the end of the throat where rifling tapers from throat or groove diameter to bore diameter.
Bellm's SAAMI chamber drawings in the post Dinny referred to show a tapered throat with a breech end ID the same as the case neck OD and tapering to ?groove diameter at the front end of the throat. I assumed this was the "long throat" you referred to above. If I understood his description correctly Bellm asserts that the rear of the throat with an ID greater than bullet OD allows the bullet to tilt before encountering the lands.
So in effect the SAAMI .357 max chamber has a throat with a forcing cone profile which does not fully support the bullet between exiting the case mouth and entering the rifled portion of the barrel. A long throat is not necessarily a tapered throat.
So, I was wondering why the SAAMI chamber throat was tapered. And ,if Bellm is correct about other SAAMI straight wall revolver cartridge chambers, why Thompson Center would use a tapered throat in their rifle barrels.
Last edited by Aagaardsporter; 04/19/24.
