My buddies 7mm STW has issues. After firing a round the bolt handle lifts fine, but the case won't extract from the chamber. We have to tap it out with a cleaning rod from the muzzle end. We have tried both Remington and Nosler brass. Seated the bullet on and off the lands. We are way below max loads according the books and chronograph. We have checked and re-checked the headspace measurements. We have cleaned the chamber several times. At this point I think it's a rough chamber. What do you all think?