Looking for someone with some knowledge on one of these rifles. A buddy has one that he's been blowing primers with Blew the tip off a firing pin. And blew a charging handle in half. All done with factory hornady ammo. Sent it back to the factory and they had there engineers look at it for about 4 months and found nothing wrong He wants to know what he can change to make it reliable. Heavier buffer spring. Heavier buffer. Adjustable gas block.??? Just looking for ideas now