I am about to begin loading some rounds for my new 284 Shehane. I made a dummy round with a piece of brass and a berger 180. At my current seater setting, I have about 0.1" inch of rifling "shine" on the bullet. Too much? Would 50 grn of R17 be about right for tight neck, turned brass,savage SA, new Douglas 1-9 barrel, with berger 168 or 180's? This my first modified chamber, so for me this is uncharted ground.