Just on the side, I have learnt that the problem with developing loads, personal experience and experience through mentoring others, is that many hand loaders simply cannot shoot well enough to prove / exploit the minute gains of these nth degree "improvements. Hand loaders often think that if they alter the jump, uniform the primer hole, uniform the primer pocket, turn the neck, neck size only, weight and sort brass etc. that their groups will miraculously close into a tight on hole clover leaf.
Many of these above techniques were honed by the 600 and 900yd shooters who would see differences. In the accuracy chain up until about 300yds, assuming you and the rifle are capable then, charge weight, bullet selection and bullet jump seem to be the big ticket numbers to getting one well sub MOA.
Personally I spent hours after hours in the beginning of my reloading career with new bullets, changing primers, you name it, when in reality at that point of my shooting experience I could only shoot 1.5MOA. After some time I realised that at 100yds precious little can go wrong, 0.1gr. charge weight difference would not be noticeable in its vertical displacement, a 2gr. case weigh difference translates to much less than that as the brass is 7X heavier than water and therefor when calculating internal case volumes in H2O that that would translate to 0.3gr, case capacity difference which is not material in the equation.
No technique or component was closing my groups. Then one day I read of a member on a local forum shooting factory ammo (which is scoffed at here due to it apparent variable quality). The best he could do was 1.5" @ 100m. In passing he was told of a National Junior Champion who happened to be on the range that day. So off this feller goes and ask the youngster to please have three shots through with his rifle, confident that he will now finally prove how poor the local ammo was. The youngster shot a 1 hole cloverleaf ...............
It was then that I realised that there was no substitute for practice. In subsequent months the more I practiced the better my reloads got (not that they changed mind).
Now this encouragement may not be for you / fit your shooting / reloading profile, if so ignore it. I encourage hand loaders now to practice more than they play with all these different techniques. I am now at the point where I can shoot 0.5MOA consistently, when on form. And it is only now that I can prove that some of the finer nuances of case prep simply have no / not enough impact at the distances I shoot at to warrant the effort.
