[Unclenick]

Islander,

(I see you edited while I was composing, so maybe you caught this already?) COL's and all other cartridge dimensions are maximums with a +0, -nnn tolerance. It is chamber dimensions that are minimums, with a +nnn, -0 tolerance. The SAAMI specifications are written that way so the largest cartridge made that meets the specification will fit the smallest chamber made that meets the specification. Also the smallest magazine, where that is applicable.


Jal5,

My first question is why you are not resizing cases? That reduces the grip on the bullet which reduces ignition consistency and accuracy, especially with slower burning powders used in full power loads. Very light target loads can be an exception both because the powder is fast and because the brass often springs back below bullet diameter after experiencing their relatively modest pressures. But full power hunting loads usually will expand the brass some. It depends on your chamber dimensions. Generally, you want as much grip on the bullet as you can get for full power loads to prevent inertial bullet pulling during recoil.

That said, perhaps you've got another reason for doing it? Just curious?

To address your original question, no, .003" difference won't matter to a revolver load in the least. I defy anyone to measure the effect on paper. But you do want your cases the same length for crimp consistency which improves ignition pressure consistency. Again, this is especially the case with slower powders like H110/296 or 2400.