Soup, haven’t used any of the N powders you’ve listed but Varget and 4895 work pretty well with the 22-250. I also can’t answer you on how accurate the Ruger will be but I’d still expect it to be a good shooter in a 22-250. I know a few folks like them a lot and have a couple fairly easy trick moves if they aren’t shooting to standard.
Even with the 14 twist you should still be good with most of the 50’s and likely with the 52 ELD and probably even the 55 grain tipped bullets as well.
I’m not sure if they are still available but Hornadys 55 grain SP might be of use to you in that gun. They are usually dirt cheap and work on varmints up through deer. They’re usually accurate as hell too.
Good luck with the #1. Hope it is a great shooting rifle.
