I was inspecting some rounds i loaded last spring for my 06 and found that half had splits from the neck to the base of the shoulder. All were done with Nosler brass, 165 gr.Hornady sst, 57.5 gr. of R.L. 19, and CCI250 mag primers. The loads shot very well, with a 3 round, 1/2 inch group at 100 yards out of my Win. model 70. Typically, if a case builds pressure due to environment changes, the primer or bullet is pushed out. what else would cause the neck and shoulder to split while sitting in a box?