Measuring Case Length

[10isnotenough]

I just got a digital caliper in order to start reloading. Just for curiosity I took out some .38 spl cases that I had saved. I decided to try out the calipers by measuring the overall length of the case.

What I don't get is that all the cases are about 1.145 inches instead of the 1.155 that I see in the manuals.

Do I not know how to measure with the calipers, or, are they not accurate, or is Federal Ballisticlean .38spl +p cases known to be short?

Thanks in advance.

 

[Jim Watson]

Manual numbers are industry maximum, not an exact spec.
In rifle calibers where stretching occurs, the trim length is usually .010" under max. You are ok.

 

[Dave R]

I have a buch of .223 brass that is significantly shorter than max. length. I guess the manifacturers want some room to grow...

 

[zeke]

Alot of manuals give the max length and the trim to or min length. For non trimmed cases, you might expect the cases not to have square mouths, and get different length measurements, depending where ya measure them (maybe up to .003 difference?)

 

[Bob F.]

See if I can stir this thread a little!??! I've been told not to worry about short 9mm cases, just don't exceed max; as long as the primer pops, the cases are long enough. But what about my rifle cases??????? I'm really trying for best accuracy and my 6.5x55 Swede cases are short!! New Winchester after being fired 1st time only measure about 2.148". Trim to is 2.150, max is 2.160". the bad part is those Swede have LONG throats; my 140gr SST's are barely in the case and still not into the lands. HELP!!

 

[zeke]

It may be unlikely you will get 140 grainers close (relatively) to the lands in a military 6.5x55. They have very long throats. Are you measuring the cases after resizing? Resize the case, load the bullets and try em, before determining if there is a problem.