Thread: Red colour inside 44-40 case??

Got some used 44-40 cases, a few of them are distinctly red inside. Wondering what powder leaves them this colour? Not my loads...

Looks like cooked brass.

May be copper due to a change in the metal caused by powder residue and moisture during storage, however it's not going to affect it's performance.

Mmm, out of a bag of a couple of hundred there are 5 of them, all Starline Brass so handloads. CAS shooter I think. Wondered if it was something to do with BP in front of smokeless or someone experimenting with fillers. Quite unusual and no, does not look like copper contamination. More like a chemical dye. Does not clean out in tumbler. Puzzling...

Originally Posted by Jhon

Mmm, out of a bag of a couple of hundred there are 5 of them, all Starline Brass so handloads. CAS shooter I think. Wondered if it was something to do with BP in front of smokeless or someone experimenting with fillers. Quite unusual and no, does not look like copper contamination. More like a chemical dye. Does not clean out in tumbler. Puzzling...

Those CAS dudes have some strange ideas, I would not be surprised by anything they get up tu.

I see a bit of that colouration in pmc brass. It’s a tarnish on older cases. No issues using them (.270Win).


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someone loaded them with BP and filled them with vinegar to remove crud perhaps????

Originally Posted by Marty Henry

May be copper due to a change in the metal caused by powder residue and moisture during storage, however it's not going to affect it's performance.

Dezincification of the brass. The zinc is mixed in to improve the brass's ductility and tensile strength - and the zinc is a lot more reactive than the rest of the bronze and other elements so corrodes out first leading to the characteristic pink colour. I am told it can be caused by breakdown of the propellant especially if there is a bit of contamination in the case - quite possible with handloads. Apparently the propellant breaks down into acid and a nonreactive component and the acid is what causes the dezincification process. Now if you've changed the components making up the brass case you've changed the ductility and strength of the case. Up to you if you want to use them, but you only get one face.

I would say they have seen vinegar after having oxidation on them I cleaned up some .308 brass to make an even 50 over the weekend that ended up the same after scrubbing the green off soap vinegar salt and water bath didn’t worry them the tumbler took it off afterwards

It looks quite minor you should see some of my 45/70s that have been left uncleaned for a while with BP residue a simple wash in vinegar and rinse and they are as good as. In in a low power/pressure round like the 44/40 you should be right as it's cosmetic.
The original cartridges of that era were made from copper.

All my black powder cases after a quick wash on Saturday are a brilliant silver/pewter colour.

Assume the acid in the BP residue has tarnished them. Another clean with stainless steel media will probably restore them to brass.
Not sure I'll bother won't affect functionality and it's quite a nice colour...

Sorry to be a "Pedantic peter " but it's a common misconception that black powder residue is acidic, it's actually slightly caustic due to potassium carbonate and sulphide in the residue. Iron and steel don't corrode in alkaline conditions. Corrosion however occasionally occurs when the sulphide gets oxidised by air to sulphite.
Not that there's much of it but smokeless powder residue is acidic.

Originally Posted by Marty Henry

Sorry to be a "Pedantic peter " but it's a common misconception that black powder residue is acidic, it's actually slightly caustic due to potassium carbonate and sulphide in the residue. Iron and steel don't corrode in alkaline conditions. Corrosion however occasionally occurs when the sulphide gets oxidised by air to sulphite.
Not that there's much of it but smokeless powder residue is acidic.

Mmmm, so why does BP residue eat the guts out of uncleaned barrels?

salt...attacts moisture VERY VERY FAST...... Black powder is made with salty stuff.

Sulphites and moisture form sulphurous acid which first neutralizes the washing soda carbonate and then does the damage to the steel. So it would appear I've kind of shot my first statement in the foot 😊 however it takes a long time for that to happen and leaving a barrel uncleaned overnight or for a day or 2 does no harm in my experience