Maximum speed with Black powder.

[john.k]

The Spanish tried to blow up a rolling block as part of selection trials ..........with barrel plugged ,and 270 gr of powder ,the gun could not be blown up.....This trial is widely documented.

[indian joe]

The Spanish tried to blow up a rolling block as part of selection trials ..........with barrel plugged ,and 270 gr of powder ,the gun could not be blown up.....This trial is widely documented.

"nothing is impossible to the willing student"
I blew the nipple out of one of my post hole guns - shredded the metal on its way out - used a half charge so 6 inches of powder then rammed in six inches of dirt over it - then spent about 15 minutes swinging the sledge hammer to drive that gun down into an old farm road bed - the mistake was the half charge - it was bottled up so tight that there was no place to go - the shredded nipple went what I believe was several hundred feet vertical, landed back with a clunk on the shed roof near me, tinkle tinkle plop right on the ground at my feet.

That roller that held either didnt have a big enough charge or wasnt plugged good enough else it would have blown.

[Sandro_ventania]

Today I watched a video on YouTube of a guy who made a .22 cal muzzleloader, with just an 18" barrel. It says in the video that he reached up to 3,200 fps with the lightest bullets.

[indian joe]

Today I watched a video on YouTube of a guy who made a .22 cal muzzleloader, with just an 18" barrel. It says in the video that he reached up to 3,200 fps with the lightest bullets.

do you believer it was straight blackpowder ?

[Boerrancher]

One thing everyone has failed to consider, is the maximum pressure that black powder is capable of achieving, which is 36,000 PSI. When the pressure reaches maximum, it stops burning until the pressure drops below max, and it is then reignited,by the heat. This cycle repeats itself until the projectile exits the muzzle, and the pressure drops to near zero, and the remaining unburnt powder ignites causing the ball of fire and sparks at the muzzle.

With this knowledge in hand, it is easy to understand why it is possible for longer barrels and lighter projectiles to gain higher velocities. It also leads one to conclude that in most of our guns, we are reaching the point of diminishing returns quicker than we realize, and are most likely burning more powder than we need. I absolutely noticed this with my Colt Walker. I don't remember the exact numbers now but the difference in velocity with a 210 gr conical with 40 grs of 3F was like 10 fps less than with 50 grs. I will gladly save 10 grs of powder per shot and give up 10-12 fps.

[Sandro_ventania]

do you believer it was straight blackpowder ?

Yes I believe. The author made another .22 gun, but with flint... and in this arrangement it seems he couldn't achieve more than 2,500fps.

[Sandro_ventania]

One thing everyone has failed to consider, is the maximum pressure that black powder is capable of achieving, which is 36,000 PSI. When the pressure reaches maximum, it stops burning until the pressure drops below max, and it is then reignited,by the heat. This cycle repeats itself until the projectile exits the muzzle, and the pressure drops to near zero, and the remaining unburnt powder ignites causing the ball of fire and sparks at the muzzle.

With this knowledge in hand, it is easy to understand why it is possible for longer barrels and lighter projectiles to gain higher velocities. It also leads one to conclude that in most of our guns, we are reaching the point of diminishing returns quicker than we realize, and are most likely burning more powder than we need. I absolutely noticed this with my Colt Walker. I don't remember the exact numbers now but the difference in velocity with a 210 gr conical with 40 grs of 3F was like 10 fps less than with 50 grs. I will gladly save 10 grs of powder per shot and give up 10-12 fps.

Friend, this information of yours is very important, it makes all the difference in understanding. Maximum 36,000psi and stops burning when it exceeds this value. Could you provide the source of this knowledge? I searched and found nothing! There is a black powder calculator, P-Max, which makes calculations showing pressures above that.

[nanuk]

One thing everyone has failed to consider, is the maximum pressure that black powder is capable of achieving, which is 36,000 PSI. When the pressure reaches maximum, it stops burning until the pressure drops below max, and it is then reignited,by the heat. This cycle repeats itself until the projectile exits the muzzle, and the pressure drops to near zero, and the remaining unburnt powder ignites causing the ball of fire and sparks at the muzzle.

With this knowledge in hand, it is easy to understand why it is possible for longer barrels and lighter projectiles to gain higher velocities. It also leads one to conclude that in most of our guns, we are reaching the point of diminishing returns quicker than we realize, and are most likely burning more powder than we need. I absolutely noticed this with my Colt Walker. I don't remember the exact numbers now but the difference in velocity with a 210 gr conical with 40 grs of 3F was like 10 fps less than with 50 grs. I will gladly save 10 grs of powder per shot and give up 10-12 fps.

I watched a program about Bull, the Big Gun designer
I always wondered how he believed he could put an object into orbit using black powder... but this explains it a bit.
a LOONNNGGGG barrel, and progressive burning BP charge.... 36kpsi over a long time could generate some serious velocity

could this be why some muzzleloaders had long barrels? to allow the use of heavier charges for greater velocity?

some interesting thoughts come to mind.

[nanuk]

There is a myth (in some places) that blackpowder cannot generate high pressure - there is enough shredded steel down the pages of history to explode that myth (literally) yet it persists in some quarters. Where does that come from? unlike high explosives (or even modern smokeless powder) black needs to be heavily confined to do its best work - I dont know the full science but its about the burn rate - ....

I believe history is full of examples of improvised explosive devices made using metal containers full of black powder.

If 36kpsi is the max BP can generate, then the container would have to be unable to hold that pressure to work as designed.

I also believe barrels that blow up due to obstructions have a different principle involved, something about the moving projectile's momentum compressing the air ahead of it. This is very different than the pressure to accelerate the projectile in the first place.