I been using the Giraud for years, works for me. Most of the time its a one time trim, without the power trimmer its a tiring chore when doing a large batch of 100 or more.
Isn't this pretty cool? Should make case trimming easier and quicker.
https://www.hornady.com/reloading/case-care/case-prep-tools/high-speed-case-trimmer
Measure the base of a few cases that you have sized and compare them to the fired cases, if any ? I would measure the base of virgin brass and see how much expansion was created at the base after firing. Just a thought
Long ago I tried 150 TSX with the 7 Mag and 7 STW ( 8mm wildcat ) , but it was so fussy to shoot well, so i dropped it never to use again. Your TSX grouping is not shabby at all. Your speed at 3190 fps is smoking. Recently I did work up a load at 95 degrees and maxed out with the 180 TTXS for...
I would not touch it imo. I rather reload the way I have reloaded my ammo using the typical brass we use. Using something new to us is not for me. I'm happy with the speed my rifles gives me, no need to go faster.