I'm scratching my head as to why someone would go through all that effort but as long as it makes your socks go up and down, have at it!!!
I can't even imagine the bolt thrust that will generate and will most likely feed like crap to boot
Completely parallel sides to cases don't help initial extraction, which is started as the bolt handle is lifted and the case "breaks" away from chamber walls and moves slightly to the rear. A tapered case does this more easily than a straight case,which drags against chamber walls.
The Brits and Germans figured this out a long time ago with the Mauser bolt system (and likely doubles and single shots as well). But they built rifles and cartridges for hunting dangerous game and wartime,where reliable function was paramount.
Americans, OTOH,don't have much game to kill so concentrate on extraneous stuff like squeezing velocity from little cases,efficiency, and other trivial distractions. Some wildcats are good examples. The 280 AI is a perfect example of this approach; the WSM's the same thing.
Sounds like the OP is trying to squeeze 7 STW performance from a short action. I hope he has fun working on it.
