Shell length.

[tim3]

Guys ive been doing well with my loads as inexperienced as i am. Ive reloaded several hundred now of several diff calibre's and all going great with min powder loads.

I see the 243 shell (as an example) is 2.045”

If i was to trim the shell to the length that the lee case trimmer die allows then it would reduce considerably less than 2.045” so is that a min or max length they quote ?

Thank you.

 

[mike in co]

it is typically the design length. when fired they grow. the chamber is designed to allow for some growth. there is also a "trim to length" typically about 10 thou or so less than design length. the lee tool will trim to about the trim to length.
when loading for rifle , one needs to pay attention to case length. the brass moves forward lengthening the case. you can get to a point where the case neck will jam in the throat and basically lock the bullet in place...which can cause a large pressure spike on firing...not good.
you can buy a tool from sinclair that allows you to measure the actual neck length of YOUR chamber, and then trim only to fit it....as in say maybe 5 thou short of actual chamber neck length.
mike in co

 

[tim3]

Thanks Mike...that explains it. I wasn't sure about trimming back past the nominal length or if so, how far. Appreciate the reply.