I've always been curious if deep seated primers could cause issues with ftf loads. For an example my prone match rifle. I use federal primers and lapua brass. Being anal with my reloading I made up a gage that uses a dial indicator to check the depth of seated primers. I aim for -.002" to -.003" primer depth on my match ammo (actually all of the ammo I load) but once in awhile they'll be a -.015" (the deepest I can measure). Those rounds are culled and marked, saved for sighter shots (or practice ammo for hunting rifles). I've never had a ftf with those rounds. Now if a rifle had a short firing pin protrusion or a weak firing pin spring and deep seated primers...
