Originally Posted by
Bert 71
Hi, a few things to check, have you dismantled and checked the bolt is clean and in good condition? Are the primer pockets clean and primers seated properly, if not fully seated the firing pin may not strike the anvil hard enough to fire. I uniform my primer pockets with a Sinclair uniformer and when the primers are seated they are a few thou below the case head and I've never had a missfire with any brand of primer. Another thing to check is if your sizing die is correctly set to give the correct head space, Erik Cortina has a good video on YouTube on setting up your full length sizing die for correct head space. I don't have the shoulder comparator for my calipers so it takes a bit more trial and error to get it to 2 thou bump. If you still have miss fires it may be faulty primers, you could also get a gunsmith to check your firing pin.