I loaded up to batches of identical ammo, treating all cases the same way and hand weighing each powder charge, with the only difference being the primer used. The load was for my 44mag using 21.2 gr H110 and a 325 gr WLNGC Bear Tooth bullet. The two primers used were the Winchester Large pistol and the CCI 350. The CCI 350 shot a cylinder into just under 2" at around 50yds in a typical clover leaf like pattern. The WLP shot its cylinder into about 3"but the bullets hit in a perfect vertical string. There was no deviation left or right just a perfect vertical string. Until I get some more components to try again doeas anyone have any idea what would cause the vertical stringing? I am begining to think it was just me.