38super

No help re powder as I don't use Viht. I can thoroughly recommend 53gr V-Max projectiles. Absolutely wonderful in my 8 twist 22BR

Viht nearest is N320. Very nice powder, just too expensive down this way 😞

Just buy it direct. I've purchased several times over the years and, Covid or not, he will send via airmail post which is still functional. I know this since I've just received 2 books in good time from the UK.

I use the RCBS automatic bench priming tool. Suffer from arthritis in my fingers and find the priming force to be gentle. The only thing I don't like is that the handle sticks well out from the bench so it's not something you can easily leave in place on the bench. Very solidly made.

There are plenty of internet articles where the fore end has been successfully stiffened using CF arrow shafts and the like. Adds weight, but certainly makes the stock far more rigid. Once that's done there's really little wrong with the pillar version of the Hogue. (ducks for cover!)

This is interesting as a subject but I wonder if the capacity differences averaged out over perhaps 15 or 20 cases will make it academic only. Where do you draw the line. Do you only measure first fired cases ? Twice or trice fired cases may have less internal volume due to powder residue. Perhaps better just to tweak QL mildly to have your results in line with load real data and carry on. I'll still be interested in the difference you see with paraffin.

I've modded mine to work with suppressors and would say that "perfect" alignment is not, in my experience, necessary for consistent reading. Have you looked at playing with the sensitivity settings. Then again, perhaps there is actually a bad electrical connection......

Just buy a factory replacement. Way cheaper than a custom barrel for your purposes. Just my 2c or maybe 2p.