Case Trimming Benchmark

[Rick Ratzlaff]

SAAMI Specs for a 243 call for maximum case length of 2.045 and minimum of 2.02 Inches.

My shortest case is 2.0385 " with 20 out of 70 cases NOT needing trimming. So I'm hearing that each case should be the same identical length. I fully understand that the case volume is still a variable. But at this point I think I need to live with that.

So my question is: Do I trim them all to my shortest case length?

 

[SteveFlock]

Since your shortest case is greater than the 2.035 trim to length and the 243 win grows pretty easily, I’d trim to your shortest case length if not the trim to length personally.

Steve

 

[Twicepop]

To answer your question, and like the previous post, yes trim all to the length of the shortest case. It has nothing to do with case capacity, it for trying to make each round identical to all the others. It is for identical bullet pull from one round to the next, if your shooting for accuracy, you're eliminating a variable.

 

[Rick Ratzlaff]

Thanks guys for confirming my logic, old as it is.

 

[MislMan]

Since the .243 cases grow pretty easily, I would trim all to a shorter length closer to the SAAMI trim-to length. That should buy you more time/firings between trimming in the future.

 

[D-4297]

By trimming to the shortest case of 2.038 , you are still towards the high end of max length , even though they will all be the same length . Since several have commented that this case does grow rapidly in length , I think I'd be tempted to take them back to a length of 2.030 , thus giving many more firings before length became a issue again . And it would give you time to "weed out" the faster growing , softer brass cases . Use them for sighters .

 

[K22]

In addition to the previous posted advice, you may want to consider purchasing a Sinclair Chamber Length Space Gauge which will provide you with the actual chamber length of your rifle thus provide less need to trim.

It isn't expensive, less than $10, and work well. Just follow the directions.