[Don Fischer]

Originally Posted by rg1

Small based dies are almost never needed loading for AR's. Most issues are with headspace and not pushing the shoulder back enough. I highly recommend Hornady's Headspace Gauge Set which works with your calipers. Without a headspace gauge you never know if you're sizing enough to avoid problems like you have. No way I know to size loaded cases. You need to pull the bullets, dump the powder, and like you mentioned remove the decapping pin. Resize the cases and use a gauge to measure the shoulders. I would recommend either Hornady's or RCBS's collet bullet puller that works in your press. Easy to pull a lot of bullets fast without damaging them. Not too expensive for the collet bullet pulling die and the Hornady Headspace gauge set. Just measure the shoulders of cases fired in your rifles, screw the sizing die in until it pushes the shoulders back 3-4 thousandths and chambering issues should go away. I suspect your cases are failing because of the shoulders too long?

Have to ask. How do you use a Hornady Headspace Gauge in a semi auto rifle? I've never used one.