I am currently chambering a nitrided Borden BRM. It is the smoothest (least prone to bind) BR action I've ever handled.
I use a Borden also BRMXD and I still use Mobil 1 on it. it was recoated and it does wear off. The oil and grease prolongs the life of the coating he uses..... jim
Got the Anschutz stuff. Applied according to instructions.
Kroil is slipperier. Next would be Steve Theye's bolt lube.
Notice I said smooth-EST
Still ain't smooth like no 30-40 Nardviggian Kragg..... nor even a Finnlander T3 built today for that matter