I have a little problem with SAAMI specifications.
Indeed I don’t understand how they specify a chamber and a ctge.
The rule when specifing the dimensions of a mechanical part (ctge, chamber or anything else relative or not to a gun) is to always give the minima and the maxima dimensions, either directly or either by adding a tolerance to the minima (or the maxima) values.
When something (a ctge for example) is designed to fit into another part (a chamber for example) it is obvious than the minimum dimension of this second part must be equal or bigger than the maximum dimension of the first part.
Let’s take a look on this SAAMI drawing:
a) the rim diameter, base diameter (diameter under the rim), case length are well specified for the ctge and the chamber.
Minima and maxima are given.
But about the rim thickness we just have a reference dimension (0.075 for the ctge and 0.0736 for the chamber)
What does it mean ???(It is never written in the SAAMI book that a reference value is a minimum)
b) The ctge must enter the chamber.
But the rim thickness of the ctge (0.075) can be bigger than the rim’s depth of the chamber (0.0736) !!
Could somebody explain me that ???