When does 230 not equal 230?

[butchd]

I'm addicted to Will Shortz puzzles. In the Speer #13 45 acp 230 jacketed bullets of various types differ from the loads for the Speer GDHP. Someone teach an old dog.

 

[BruceM]

The shape of the bullet changes the depth to which the bullet is seated in the case and the length of the bullet's bearing surface in the bore. Both of these will change chamber pressures.



Bruce

 

[Gun 4 Fun]

The jacket material will also change pressures with an identical load. (plated vs. gilding metal drawn cup)