A buddy of mine has a 1995 model 110 in 308, the bolt is sticking plus someone has ground the rear of the locking lug area, I guess trying to stop the sticky bolt. This was discovered one day at the range, what I was wondering what needs to be done as far as replacing the bolt head, being the firing pin is larger on the older model 110 is it safe to drill or just buy another pin assy? He really doesn't want to drill is there any secrets that are safe?