“If its worth doing, it's worth doing right”
Kraigwy, I agree, again, what model of Mauser? There are barrels for replacement, I have little interest in restoring to military configuration, I was at the Dallas Market Hall Gun Show this last week end, a dealer came by and was complaining about the rifle he had found, a magnificent Mauser that was drilled and tapped with a mount, rings and scope, a nice shiny barrel with a a very expensive looking stock, his opening statement went something like “Look what someone did to a very rare Mauser”, I reminded him the rifle belong to to the builder, it was his option to do as he pleased, If I need a M1917 action the ears are coming off, those that inflate the value do not will not pay the price.
Bore to? When counter boring the diameter should be adequate, the bullet is leaving the barrel, what the bullet does not need is gas escaping when the bullet leaves the bore, escaping gas can kick the rear of the bullet, the largest diameter counter bore possible is best, in my opinion, I have two that exceed .400”. the two counter bored rifles I have were counter bored because something ran into the muzzle, not because of a tapered bore at the muzzle. If the counter bore bothered me I would replace the barrel, again, there is risk, the rifle may not go back together looking like it did before I started.