I have had serious problems with Winchester large pistol primers both jamming in my loading tubes and in my feeder tube on my Dillon SDB. I have now used about 3k CCI primers with not one jam. Believe me I went through hell trying to figure it out, I measured, looped, and lubed (figuritivly speaking of course) the d@mn things and even tried to run a .22 brass brush down my tubes thinking I had done something to foul them up. I still have no idea but I do have a lot of Winchester primers in the scrap pile
Dave