Jerry,
This is going to sound weird, but it is true.
I full size for my 7mm Weatherby because many of my previously fired cases do not fit in the chamber without some serious cam action. My empirical, unscientific evidence indicates that nearly 48% of my fired Weatherby cases will not chamber correctly without a full-length resize. I performed the following test to determine why the cases would not chamber correct after a large number of neck sized reloads with a correct OAL failed to chamber without "cramming."
My test was to chamber fired brass and determine if a fired case would easily chamber in my Remington 700 Classic. First, I selected 3 sets of 5 cases for my tests. All tests were conducted with clean fired Weatherby brass with a case length under 2.549". I then put the muzzle to the floor and allowed the cases to slide into the chamber until it went no further. Next, I attempted to close the bolt. About 50% of my cases did not chamber. After I discovered that most chambering failures occurred with Weatherby brass, I re-performed using a 100% sample of the Weatherby brass. During my subsequent testing is when I derived the 48% number for Weatherby brass. The R-P and PMC fired cases seemed to be much better, but they still did not always work properly.
The cases that were tested had been re-loaded with 68.5 gr. IMR4831, CCI Large Magnum Rifle primers, and topped off with 140 gr. Ballistic Tips. During the reloading process I did not sort the cases and test by lot nor did I notice if any of the cases were difficult to extract. All primers (and I know that this is not fool proof) were still rounded.
Since I have not had this trouble with either the 308 Winchester, 30-06, or 25-06, I surmised that maybe magnums were not a candidate for neck sizing. But then that conclusion runs counter to the experiences shared on this forum.
/ubbthreads/images/graemlins/confused.gif REO