Do you have way to measure shoulder bump accurately? It needs to measure from the actual datum. If so, measure both the case and the headspace gauge. The brass is big or the chamber is small...one or the other. You're going to have to be able to size the brass down, and right now, you are not sizing it enough for your chamber. if that piece of brass has NOT been fired or sized, AND the go gauge/no-go gauge says it's good( assuming the headspace gauge is correct)....the chamber must be small at the shoulder/body junction. You could get the same kind of result from brass that is run into a die, but not enough to bump the shoulder back, but that's hard to imagine on virgin brass. If everything checks out, custom dies may be in your future. Small chambers require smaller dies. Good brass life is a result of proper die to chamber relationship(and good brass). I'd opt to make the chamber fit the die, particularly on a varmint rifle. Small chambers can cause just as much, or more headache as big ones. Too big, brass life suffers...Too small, and you get bolt lift problems that require expensive custom dies to address. I like to spec reamers to my dies. Not the other way around as is so very common. of course being a Savage, you might be able to address it with the barrel nut...not preferred.