I have had excellent results with LMF browning. Ignore the copper areas, that will happen for the first couple of coats. The barrel will look ruined at first but it is far from it so keep going. On about the third you'll see those areas pretty much gone and by the forth completely gone. You do not have to ultra clean the barrel surface, I swipe mine with acetone before beginning and use rubber gloves thereafter to handle the metal. The process is to use a sterile 100% cotton ball (drug store, pharmacy), which I apply the LMF to by simply covering the open bottle top with the cotton and turning it up side down for a second. Use the lightest pressure you are capable of when applying it, you can recoat small missed areas as you go. I overlap each finished area each time I apply until the surface is done. Give that first coat 4 to 6 hours to "cook." More if you have low humidity, it is not critical. For your second and third coats just the LMF without carding. On the forth application card if you wish, if you do not card your finished barrel will be rougher than if you do card which gives a smoother finish. Your choice. Between applications you can leave one overnight if needed, the LMF is very forgiving.
It usually takes 6 to 8 applications to build a good browned surface, in any case it will reach a point where further browning isn't happening, or at least isn't noticeable. Wipe the barrel down with ammonia, let it dry well.
At this point you can stop for a "browned" barrel (metal parts) or continue to a Boiled Black. If brown is what you want then the barrel needs to be heated until it is hard to touch, then oiled and left to cool. If it smokes some when you apply the oil - great.
LMF Browning WILL work and is a good choice; ignore the copper salts the first few applications and continue to brown, overlapping is ok, do not rush the process. The solution is quite forgiving.
If you want a rougher "aged" look PM me and we'll discuss that process.
dave
