Usually it is the angle of the sear tip in relation to the hammer bent.

I often see sears that have been bent slightly to reduce sear engagement as well, this leads to a very dangerous situation where the sear tip is not seated fully in to the hammer bent. I just had one in last week like that from a long time client, I straightened the sear and the problem was resolved.

Those are the two most common sources of doubling in my experience.

I'm sure someone will be along shortly to correct me.

Firearms imports, consignments


[Linked Image from i.imgur.com]