Question about neck tension
New to rifle loading. Wondering how much I should worry about neck tension/diameter. I’ve read to go for .001-.003 but after sizing my brass for 257wby, my necks int/ext are .250/.280. As I’m new to rifle loading I’m not super worried about exact consistency just yet, but wondering if those numbers would be ok/good/safe to just make my first and test them out? How much of a difference will getting into the extreme precision of neck tension make for my maximum of 3-400 yard shots?
Thanks in advance