Brownell Formula 44/40 Instant Gun Blue

Absolutely one of the best chemical blueing agents I have ever found.

from what i had seen online from ppl using stuff like this, not this very brand just a solution to black metal, had trouble getting the parts to come out all the same, one would be covered an the next would be blotchy so i didnt know what to expect. when i cut the foil seal off the tip of my blade was blade when i pulled it back so i knew it worked but didnt see how well it worked til i brushed a little onto a toe clamp i had made an it really was instant an didnt take near as much as i expected. i didnt want to dunk the hole part in the solution so i was just brushing it on an this will be the method i use from now on unless i run across a large part or something but this stuff works really well an if ur looking to black some metal parts this works. buying it in small 2oz bottles is probably not the best way if u have alot of parts or large parts but i will be sticking with this brand.

good product

Works exactly as advertised. I used the cold blue to touch up sharpening errors I had made on two former USMC Mk2 "KA-BAR" knives (a Conetta and an M.S.I. with 1095 steel blades). Instantly blued to a finish very similar to the existing Parkerizing on the blades and allowed me to resharpen to achieve a sharp edge with about 1mm of shiny, sharpened edge showing...just like the factory did it all those years ago. Best cold blue I have found.

A good buy

I bought this after getting a shotgun which was marred by rust which destroyed the finish. Just horribly maintained. The barrel wasn't rusted through, mind you, but it had penetrated deep enough that once the rust was removed, patches of the finish were nonexistent. I bought Brownell Formula 44/40 as a fairly cheap method of restoring a good look to the shotgun. What did I really have to lose? less than $13.00 isn't a lot of money, after all. All it took was applying it to a patch, and running it along the affected areas, and the blackness lost to the rust was restored. It's not absolutely perfect, of course, but close enough that anyone who isn't looking for a difference won't notice. And I imagine applying more of it would darken it further, but what has already been done has satisfied me.

This stuff reacts instantly and is very forgiving. I use alcohol or mineral spirits to prep metal surfaces on my blacksmithing projects and get great results from this. You don’t have to do multiple coats either to get good finishes. 1 bottle lasts a while and be sure to change your application instrument (swab or cotton ball) after each use or you can contaminate the fluid.

I'm a gunsmith, and use Brownell's products often. I heard and read about 44/40 and thought to try it on my own shotgun. I typically only cold blue when either the customer is looking to save a little money, it's not a large surface area, the blued steel isn't being handled or there will not be a lot of wear. I stay away from cold bluing pistol frames and slides because it wears off very quickly. Anyway, the first application of using 44/40 I was very impressed with how quickly it worked and how black the part appeared to be. This was done on a Mossberg 500 20 gauge magazine tube and field barrel. However my first impression changed once the part was rinsed and oil was applied to set the finish. The barrel needed to be completely stripped again, it looked horrible. However I had thought the magazine tube would be OK at that time. I was wrong, that needs to be stripped again and refinished. It went from a solid black to a blotchy gray with a lot of weird patches of dark/gray areas. It reminded me of using Super Blue by Birchwood/Casey. Stick with either Oxpho-Blue or Van's for cold bluing. I re-blued the barrel using oxpho-blue and it came out perfect.