New Sendero

[Gotcha!]

Originally posted by SuicidJky
ya your right, going down to the lowest can't be the right place to start, and there test rifle being a model 700 with a 24 inch barrel and a 1-9.25 isn't remotely close to my sendero's 1-9.25 twist 24 inch barrel. I loaded some 139's down to 50 grains, which should be in the neighbourhood of 2400fps, with new brass....the marks were still there...looking exactly like the rest of them. with once fired brass they were gone and the base looked flat and like any normal case.

With this additional info I suspect the NEW brass is too short for your chamber, and it is being SLAMMED into the bolt face, The lack of marks on reloads in once fired means you now have the brass fireformed and everything is working as it should. Work forward from the once fired stuff.