Shoot over snow to find the right load:
This one goes on the assumption that all black powder is burned up each time with a 'good' load. The theory here is that if there is umburned powder laying on the snow you are using too much. You are suppose to keep cutting down until there is no unburned grains showing. No so. Every time you shoot black powder some unburned powder results. Another thing that is not realized. When the unburned grains of powder go out the barrel they often burn up in the air. Any that might make it to the snow will be hot enough to dissappear into the snow. The best way to find the load for your rifle is to go by the manufacturers recommendation or a hand loaders manual.
No matter what the brand, all Black Powder is the same:
Since the formula for Back Powder has been set for centuries one could see where this might be true. If it says FFF is should be the same as any other brand that says FFF.
Not so. Just like one lot of smokeless powder can vary from lot to lot so can the brands of Black Powder. And especially the substitute Black Powders.
Always start low and work your load up, no matter what the book says. You may find that your rifle likes one brand better than an other. And shoots to the same point of aim with less powder.
A sure fire way to abtain the right load for your rifle is to put the ball in your hand and pour powder over it until it is covered:
Please do not shoot your rifle around me if you use this method. Too many varibles. My narrow hand cupped vrs. Myrights wide hand held flat could be a difference of 20 grains of powder. Do you think that much won't matter?
A muzzle loader can not be overloaded.
The theory here is that any excessive powder will be blown out of the barrel. Not so. There again is a lot of varibles here. Such as the diameter of the ball, the thickness of the patch, the roughness or amount of fouling in the bore. All will cause resistance that will slow the movement of the patched ball, cause more pressure and allow more powder to burn. I have seen too many muzzle loaders with bulged barrels or replace barrels and forearms to believe in this idea.
Light loads are more accurate.
Not necessarily. Sometimes but not always. The best thing to do is find what your rifle shoots better with. I always start low and then work up until the groups begin to open up. Some times that happens before the load gets heavy and some time after the load begins to kick. You can't tell until you test YOUR rifle. Sometime more powder will actually reduce velocity.
A small amount of Smokeless Powder will have the same pressure as a larger amount of Black Powder:
If you believe in this myth, I would like to buy what is left of your rifle to demonstate to my firearms safety students what you are not to use in black powder guns.
Black Powder explodes at about 15,000 PSI. Smokeless pistol powder burns at about 35,000 psi and smokeless rifle powder burns at up to 65,000 psi. Any smokeless powder is too much pressure. And it is the pressure curve that blows the gun. Meaning the pressure builds and builds and builds. The Black Powder guns are built to take a quick short pressure curve as Black Powder does.
Hope you like these myths, I haven't touched on Muzzle Loaders very much in this board.