They make good primers to use for fireforming or something less than full accuracy needed sorta dutys. I typically clean up random stuff with the Mashburn when I fireform cases..I took bolt apart and firing pin hole was clear and no crud but cleaned again just to be sure, put back together with no lube. After measuring the diameter of these primers, I thought maybe it was causing a problem with the anvil or priming compound by being hard to seat. Just a guess. Using the same brass, the newer primers fall in, so this makes me think brass is fatigued. Have annealed it before full length sized then trimmed. Wild thing is these old primers have given good groups with this rifle and another. Not ruling out the problem was me, but I did sight in another rifle prior to the 270 and it grouped as good as always. Might be best to quit using them and put back on the shelf. Dan.