I just realized you are going to mag feed your cartridges, in which case,
I would suggest investing in some of those different height shell holders from, Redding, I believe. These allow you to run the case all the way up in the die, completely sizing the entire length of the neck. I single load my rifle, so neck tension under recoil is not a concern to me. The method I use to bump shoulders back leaves a bit of the neck unsized. Probably not good in a magazine fed rifle , dont know. Probably better to buy the right stuff.