Im putting a new sear in my lyman great plains, do i need to india stone the sear cause of metal to metal contact?
Thank you
IMO, if the new sear is from Lyman, you shouldn't have to do anything special. The Sear should already be hardened and machined to the point that it works just like the factory gun.
You could use a very fine oil stone to polish the nose of the sear but usually that doesn't gain much and it opens the door to you inadvertently changing the angle of the nose. That can make things worse.
Keep in mind, the sear must be capable of moving freely after it is installed. That means, the screw that goes thru the sear and holds it in place should be tightened up to a "snug" condition but no more than that. Do
not overtighten it. After it is installed, use your finger to move it. There should be very little resistance except for the force on it from the sear spring.