7mm SAUM: Sorting cases by neck thickness

[plumbs7]

Hey Albert,
Our sport is the pursuit of perfection, like all sports.
Trick is knowing what really matters or what gives the greatest return for where the shooter is in their journey to "near perfection".
I'd suggest loading all the cases and see if the ones with a different neck wall give a measurable variation.
Or keep them for shorter ranges and reserve your best ones for the longer ranges.
Some of the best shooters don't neck turn at all.
I neck turn my 7saum and don't neck turn my 280AI, both shoot way better than I can.

Hi Albert , I second Tim's wise words ! It is hard to know what counts and what doesn't and both ways or a number of others will achieve the same result. You must be shooting very well to win your first entered prize meet . That is not an easy feat! Took me 3 years to do the same ! So for what it is worth I'll tell what I do for the longs in case prep .

I'll weight sort brass from lowest to highest ( if I have time ) ! I'll batch bullets from base to metplate in 30 thou lots . I'll then match the longest projectile with the lightest case ,all the way to the shortest projectile to the heaviest case . Projectiles are all pointed . I don't turn necks in a no turn neck chamber with lap brass . Inside necks are champhered . With lap brass I don't touch the pockets as B Litz found that leaving the primer pockets that are drilled and untouched give the lowest SD.
Primers are weighed but not anal ! Each charge is weighed to the granul , then 9 times out of ten it's soft jump or jammed or 5 though jammed.

The tolerance of 1/2 thou in neck thickness maybe better delt with annealing. So the neck can expand evenly . You already have the magic 10 fps spread for 5 shots which is an indicator. But that might blow out to 15-17 fps over 30 shots . This where SD maybe better indication of what is going to happen. Also it's unrealistic to expect an SD of 3 over 30 shots . Atmospheric conditions and even chrony errors will change things . There is some trade secrets I've just given away and I hope they help . I just don't want to see you get burnt out chasing absolute perfection. When it maybe better spent shooting in tough conditions. All the best Albert , I'm sure we will meet on a mound somewhere soon and you can teach me a lesson Lol! regards Graham.