RE: 3 N 1 Oil
 

I have used Militec synthetic metal conditioner for about 20 years. The stuff lasts a long time.Many of my guns have been untended and unused for a couple of years at a time with noproblem ever. Be sure to get it completely out of your muzzleloader bore before shooting the gun or you will have the crud ring from hell.

http://www.militec1.com/