Wrong place for this posting but your title caught my eye.. So far, Brownells Oxpho Blue has been the best product I've found for cold bluing.. I used to use Birchwood Casey but the Oxpho Blue is more forgiving as far as prep is concerned (still need to be very anal with prep though) and leaves a nice dark finish. Heating the metal prior to application using a hair drier or something similar will make it even better..I want to re-blue an older savage mod. 29b .22, and possibly repair some rust on a Browning 30.06 BAR Mk II.
Agreed but be careful to use ONLY 0000 steel wool.. I'd also suggest using an oil at the same time.. I've been restoring firearms for several years now and do know a little bit about this.. I always try to promote a hot bluing for a true professional job but for weapons that hold more sentimental value than true collectors value, nothing beats a good cold blue restoration.. For deeper rust or pitting, all can be removed by a process called draw filing. I've used this process on both flat and round surfaces with great success.The only way to repair rust is to cut it out. If it's very light surface rust it can be steel wooled.