Ok I have a 22-250 Ackley .250" neck diameter loaded. .002" neck tension is where it is sized with standard dies and shoots lights out. But how much does the brass spring back during resizing? Do I order a .248, .247, .246? Thanks in advance guy's.
What you want to do is have a loaded round or dummy round of the bullet you intend to shoot is the brass you intend to shoot it in. Measure the outside of the case where the bullet is seated. Then subtract .002 and that's the bushing you want. So for your round if it's .250 subtract .002 and you want the .248.
With a .250" loaded neck I would get a .248 bushing. Some people like to tinker so they might get a .249 and .247 to go along with it. You may need something like those down the road if you get new brass with a different thickness, but for where you are, I'd go with .248 bushing if you were only going to get one.