BobZ being one who has spent countless hours at the range trying prove or disapproved countless and assorted variables to myself to eliminate I have taken a case rotated it a 1/4 turn each shot and it will form a circle around the 25 ring. I have done it so many times over the years and at times just to show someone the effects that I have proven it to hold true to myself beyond any doubt. But it is also if you think about it really meaningless as it only verifies the need for one to index his case if only using just the one. If using multiple cases it then becomes a real big concern all together in that it can and will drop points intead of gaining them. 

JLouis 

Seems the important issue for serious shooters is indexing cases not turning the necks. Really doesn't matter if it's off to one direction as long as all of the shots are there and you center them.

CW I have a real nice shooting case and might try turning it all though I hate to go through the process of finding another just like it should I take the edge off it.  Some shoot extemely well and some just won't shoot that well at all and are just thrown away.

JLouis

JL - I have lots of outside neck turning stuff (mandrels and cutters and 'lathe').  The person who showed me how to use it (on 6ppc) said to trim only the minimum amount.  (The rifle had a .264" dia neck area in the chamber and the finished ctgs were setup so there was 0.001" on the diameter.  I consider that absolute minimum.

One other facet are the Wilson neck sizers - with the inserts sizing just the front half of the neck.  That leaves the area from the middle of the neck down to the juncture with the shoulder at 'full' size.  That I presume would center the assembly in the chamber.

Keith thanks for chiming in and I agree with what you noted as being related and I don't think it overly usual to have all three of them taking place in a single case. Back when Jan / Jack Hughes was still shooting his 32-20 CPA using multiple cases I watched him shoot to sort and toss the cases that would not into the recycle bin. And also probably more than some might actually come to realize if they have even heard of such a thing as a bad shooting case until now while breech seating. He is indeed the expert on that subject having shot well over forty 250's in practice if memory serves me right as well as being shot back to back and maybe he will chime and share his findings if not his Ace in hole and one not to be shown. 

JLouis

I carried the practice of numbering cases over from archery, where it was common to find one or two arrows out of a dozen that just would not go where you wanted.

This has eliminated an unexplained flyer more than once.

Dellet wrote on May 24^th, 2018 at 10:05pm:

Wish I could figure out how to sort .22 RF like that 

In heavy class CBA it is also quite common for a 30BR case to go sour before finishing a match and generally the top competitiors will have three good shooting cases already shot sorted on hand. Not trying to confuse things but just pointing out that a good shooting case can also turn into a not so good shooting case while trying not to get to far off subject.

JLouis