Hi, I am a newbie of reloading world.
So, I’d like to check my understanding of reloading terms and knowledge.
A. Shoulder Bump
What is the standard for -0.002?. For example, I have 6.5CM Aero Solus. Once I fired, the brasses will be stretched out, not the same length, from the base to neck, It might be various like 1.536” to 1.538”. So, how should I do then. Put the FL sizing die into press, and makes all brasses into 1.534”?
Or
If I have a factory brass, never fired brass, Hornady Brass, put that brass into Hornady headspacer, and make caliper in zero. So, the never fired brass, is in 0.000. After that, all fired brass, and make them into -0.002 through the FL sizing die. is that right?
B. Neck tension.
I have a Hornady Custom Grade die for 6.5CM. But, I will return it cuz, I am thinking about purchasing the Forster Full length “Bushing” die, cuz I want to put the neck tension too.
Same like Shoulder bump, I need to check the diameter of the 6.5CM brass neck, so, if it is 0.409. By using Full Length “Bushing”die, make it to 0.407. is that right?
Or, I have a Lee ultimate neck sizing die. Can I use this one too?
Make it simple that
1. Just using a Full length “Bushing” Die, so that you can do the shoulder bump + giving neck tension in one action OR
2. By using Full length sizing die, make it shoulder bump, and change the Neck sizing die, and giving neck tension.
C. Load Development.
So, I am gonna use H4350, starting from 36Gr, increase by 0.3 grs, not reach up to maximum grains, 40grs. After I shoot 5 shots of each powder mass. I can get the result of ES/SD/ and Group Size. So, my question is, which factors is most important? ES/SD or Group size?
If I knew the best value of ES/SD or Group size, then I will decide the “Seating depth”. Am I understanding correctly?