I truly wish several here on the Fire would purchase some pressure testing equipment. And spend a fair amount of time and money learning how to use it. And I promise, it will be more time and money than you think. One of the most eye opening things I learned first, was that the electric grid in the US has far too swings to be able to use for this type testing. At least in Kentucky and Texas.
And test a lot of different cartridges and powders and bullets. Then, start trying to test primers. That's a real head scratcher.
I used to think I knew a lot about handloading and such until I went down this path.
Charlie

The data and opinions contained in these posts are the results of experiences with my equipment. NO CONCLUSIONS SHOULD BE DRAWN FROM ANY DATA PRESENTED, DO NOT, UNDER ANY CIRCUMSTANCES, ATTEMPT TO REPLICATE THESE RESULTSj