Originally Posted by SPR123
I understand that just velocity increase is not the only evaluation. How would you go about finding the "Happy" load for a new cartridge such as the 7mmLRM?
Here's a simple way that works for many. With Retumbo, I'd start with the equivalent charge weight to your H1000 load and work up in .5 grain increments until you start seeing pressure signs. (ie ejector marks, hard bolt lift) Once you hit pressure, back down to the next lower increment and evaluate accuracy. There should be an accuracy node close. Once you find the node begin to fine tune by changing seating depth, primers, etc. For expectation management, your Retumbo load should end up weighing 1 to 2 grains more than your H1000 load.