overall case length question

[Rocky Raab]

I'm kind of a maverick in this bullet-land gap thing. I don't care what the jump is.

When I start loading for a new gun or new cartridge, I first set the OAL at the book number. That's set by SAAMI at a point where it will be safe in any gun with a standard chamber.

Then I shoot it and note the group size. I'll work up to a safe load with good accuracy first. Now, I'll try two different seating depths, one a bit deeper and one with a bit longer OAL. Normally, I'll go .020" each way.

Shoot again and see if there's an accuracy change. If there is, I'll try a third batch 0.10" either way off the more accurate depth. Again, if there's a most accurate one, I'll settle on it. (At this point that would be the most accurate of five attampts at OAL, if you follow.)

Now I'll determine the loaded length from case head to a standard datum: the bore diameter. I explain all this on my web page, and it's too lengthy to repeat here. But from here, I can load an accurate depth with ANY different bullet with no trials at all.