Overloading BP - The Firearms Forum

Birdseye · 10-21-2008, 06:44 AM

Hi all.

If you Google "BP Overload" you will get a series of responses that appear to be about equally divided between "You can't" and "Whooooooooa, you'll kill yourself".

I am trying to get a definative answer to the question "what happens when an arm is loaded with more powder than your Mom would like to see you load into it".

I don't care about things that "might" blow out like nipples and breech plugs. Assume we have a 5 ft by 5 ft by 20 ft block of steel that has been bored to .5 in.

Assume that we can magically increase the depth of the bore to say 10 ft.

Now for each bore length/bore depth/loading we measure

1- muzzle velocity
2- weight of non burned powder.
3- pressure over time

What are the results. No dire explosions here.

At some point the pressure will be great enough to expel all unburned powder (and the ball). What is the load (in a .5 in bore) where this occurs?

Equations would be really nice but word pictures will be fine too.

Thanks.

Ed

Buffalochip · 10-30-2008, 09:30 AM

Ed,
It doesn 't look like anyone intends on answering your question. But, if you are wondering how to determine the maximum powder your muzzleloader can burn, here is one way the old timers did it--at least this is what I read when I was a kid. From a prone position on a field of snow, you fire your rifle parallel with the ground, check for unburnt powder, increase the load slightly, check for unburnt powder, etc., etc. until you see unburnt powder on the snow. Now you know how much powder your muzzleloader consumes before it blows unused powder out the barrel.

As far as determining whether or not you can or cannot overload a barrel, I have an old blackpowder shotgun with a bulged barrel and know a man who has an original flintlock pistol he inherited from his grandfather, a physician, with a blown out barrel on the left side, just opposite the lock. So, yeah, you can blow up a blackpowder barrel.
Chip

Roy · 10-31-2008, 01:06 PM

I remember reading an article in a Dixie Gun Works catalog describing a barrel test. Apparently, after filling the barrel with black powder (!) they put a breach plug on each end then touched it off through the vent hole. They couldn't believe that all the smoke and flame exited the vent and did no damage to the barrel. Incredible if true!

Having been a black powder shooter for over 30 years, I'd say as long as you use reasonable loads and THE BARREL HAS NO DEFECTS, you'll be fine. As eveyone knows, old damascus barrels should never be considered same to shoot. Sorry I don't have any formulae for you, just this anecdote, but there you go.

10-21-2008, 06:44 AM	#1
Birdseye Member Join Date: Oct 2008 Posts: 3	Overloading BP Hi all. If you Google "BP Overload" you will get a series of responses that appear to be about equally divided between "You can't" and "Whooooooooa, you'll kill yourself". I am trying to get a definative answer to the question "what happens when an arm is loaded with more powder than your Mom would like to see you load into it". I don't care about things that "might" blow out like nipples and breech plugs. Assume we have a 5 ft by 5 ft by 20 ft block of steel that has been bored to .5 in. Assume that we can magically increase the depth of the bore to say 10 ft. Now for each bore length/bore depth/loading we measure 1- muzzle velocity 2- weight of non burned powder. 3- pressure over time What are the results. No dire explosions here. At some point the pressure will be great enough to expel all unburned powder (and the ball). What is the load (in a .5 in bore) where this occurs? Equations would be really nice but word pictures will be fine too. Thanks. Ed -->

10-30-2008, 09:30 AM	#2
Buffalochip Senior Member Join Date: Oct 2008 Posts: 754	Re: Overloading BP Ed, It doesn 't look like anyone intends on answering your question. But, if you are wondering how to determine the maximum powder your muzzleloader can burn, here is one way the old timers did it--at least this is what I read when I was a kid. From a prone position on a field of snow, you fire your rifle parallel with the ground, check for unburnt powder, increase the load slightly, check for unburnt powder, etc., etc. until you see unburnt powder on the snow. Now you know how much powder your muzzleloader consumes before it blows unused powder out the barrel. As far as determining whether or not you can or cannot overload a barrel, I have an old blackpowder shotgun with a bulged barrel and know a man who has an original flintlock pistol he inherited from his grandfather, a physician, with a blown out barrel on the left side, just opposite the lock. So, yeah, you can blow up a blackpowder barrel. Chip

10-31-2008, 01:06 PM	#3
Roy Member Join Date: Oct 2008 Location: Texas Posts: 10	Re: Overloading BP I remember reading an article in a Dixie Gun Works catalog describing a barrel test. Apparently, after filling the barrel with black powder (!) they put a breach plug on each end then touched it off through the vent hole. They couldn't believe that all the smoke and flame exited the vent and did no damage to the barrel. Incredible if true! Having been a black powder shooter for over 30 years, I'd say as long as you use reasonable loads and THE BARREL HAS NO DEFECTS, you'll be fine. As eveyone knows, old damascus barrels should never be considered same to shoot. Sorry I don't have any formulae for you, just this anecdote, but there you go.