For years i have left my muzzleloaders loaded for extended periods of time. My guns were always loaded on clean barrels.


Some time ago i noticed some very fine pitting and a frosted appearance of the metal in the powder chamber of my TC Encore. Recently noticed the same condition in my TC Black Diamond. That fine pitting and the associated frosting is caused by potassium perchlorate.


Except for BH 209 all the black powder substitutes contain potassium perchlorate in varying quantities. Yep, Pyrodex, Triple Seven and all the APP powders (APP, JSG, Pinnacle and Black MZ) contain potassium perchlorate.


You may ask why these substitute powders contain potassium perchlorate. Answer: It's an inexpensive way of boosting the puissance of the powder.


Henceforth i will not leave my muzzleloaders loaded for extended periods of time.

I know people leave their muzzle loaders charged for extended periods of time. And that's fine, its their gun. I never do. But I do this more for a safety reason. And I see no need to leave a gun loaded as I clean them once I come in from hunting and shooting. It does not surprise me that this would happen like you described. Good information there !!

Falcon - BH-209 does contain Potassium Nitrate as shown in a chemical analysis.

Just out of curiosity... were these blued barrels or stainless... I ask because I have done and do the same as you indicate but I even go one step down the ladder further - I do not shoot a clean barrel while hunting - it is always what I call semi-fouled. I am shooting T7.


So far.... and I am knocking on wood, I have not found or ran into this problem.

I have never left my MLs loaded for more than a couple weeks. That is until this year. I have one of my flinters setting at home on the rack that is loaded with BP. But I'm not worried because although the bore was swabbed prior to loading with a dry patch to remove excess oil the bore was otherwise clean.

They are blued barrels.


i've always left my guns loaded for extended periods of time. Never had a problem when using Pyrodex or Triple Seven. The corrosive effect of the potassium perchlorate in those powders may be mitigated by the sodium benzoate.


IMO: Black MZ must contain a huge quantity of potassium perchlorate.