If the rim headspace is fairly tight, I don't think you'll see a lot of stretching either, but of course, that might depend on the brass and pressures generated.
With a good tight neck fit, crimping might not be necessary, however it helps the powder burn in these straight cases.

further, I think you should be able to run 350's at about 2,350fps, with pressures in the 40,000range - just guessing, using powders like H4895 - and maybe Reloader #17 - however I have no data on those for this round.