Why The Lack Of Concern/Info For BP or Equivalent Load Pressure Levels?

[gmerkt]

Black powder has a slower burning rate than smokeless, which decreases the pressure that forms under the projectile. This same phenomenon may be observed within the range of extruded smokeless powder burning rates. I.e., you can fill a CF case with a slow powder like IMR 4831, and it will still be below the pressure of the same cartridge loaded with a smaller quantity of faster burning power that is maxed out on pressure.

I've tested my BP rifle over a chronograph where I reached a point that velocity would not go up further - the excess powder was simply blowing out the end of the muzzle. I was still far below what the manufacturer listed as a maximum charge for the rifle, so went up some distance confirming this effect.

BP will only burn X fast, and after that point the excess powder cannot combust and raise pressures any higher. This is one reason why shotgun reloading data needs to be followed fairly closely.

Other factors mentioned above are also valid within the same concept. Slower powder is giving the bullet a gentler push out the barrel; the faster powder wants to spank it out. Likewise, a bullet with a full skirt creates more internal bore friction than a round ball, which increases pressure. Jacketed bullets, more pressure still.

 

[P7M13]

@arakboss , you ever hear of "Kentucky windage"? You've been standing downwind of the treatment plant by Fred Meyer for too long.

But, if you still want to know how much pressure may be generated, download Gordon't Reloading Tool (free). It does internal ballistic calculations, and may include data for black powder.
"Thimble-fulls" don't mean squat when it comes to math. You need hard values with actual units to gain some accuracy for your calculations if you want to keep your eyes and digits intact.

Edit to add: before you do any of this ("don't try this at home, Kids!"), your wife will appreciate that your Life and AD&D policies are current.

 

[dangerranger60]

I am looking at picking up one these style of revolvers made by Pietta (44cal).

View attachment 1871492


Any idea what the maximum pressure is that this style of revolver will handle?

I'm not sure you could overload the chamber and still seat a ball deep enough to get the cylinder to turn.
45 colt in its BP loading was a case full of BP minus just enough to seat the powder without crushing. it doesn't leave much room to overload.
Now when I load a fast-burning smokeless powder in a 45-colt case there is room easily to double charge and with some powders there is room for a triple charge. DR

 

[dangerranger60]

One idea I had for a 410 load was a full 2.5" brass shell worth of Pyrodex RS under a full 2.5" brass shell worth of shot. I would load the powder in the case and insert an over powder wad to hold it in. After inserting the shell in the shotgun, I would load the shot in from muzzle and top it off with over shot wad. Any idea on what type of pressure that might make?

Part of making an effective shotgun round is making a balanced load. too much pressure, too much shot, or getting these out of balance either has the shot dribbling out of the barrel, a slow-moving shot column with a rainbow trajectory, or as the pressure builds up you get a donut shaped pattern on target. DR

 

[arakboss]

Part of making an effective shotgun round is making a balanced load. too much pressure, too much shot, or getting these out of balance either has the shot dribbling out of the barrel, a slow-moving shot column with a rainbow trajectory, or as the pressure builds up you get a donut shaped pattern on target.

The 410 load I proposed, should be considered a square load. I could start with less bp and work my way up or less shot and work my way up. I recently acquired a cheap stainless 410 break open and think it would make a good host for trying some stout BP loads.

 

[arakboss]

On another less pressure related bp topic: Would the priming compound in a 22lr case be strong enough to light off a load of BP? If so, this could open up a whole new avenue of small bore bp load options.

 

[Lilhigbee]

On another less pressure related bp topic: Would the priming compound in a 22lr case be strong enough to light off a load of BP? If so, this could open up a whole new avenue of small bore bp load options.

The original rimfires WERE black powder loads. Not sure if the priming compound is the same today though.

 

[salmon creek gary]

@arakboss
If you want some good information about muzzle loading firearms , pressures and load data...
I'd suggest buying a copy of :
Lyman Black Powder Handbook.

I think it is out of print...and while some of the information is dated , in regards to firearm manufacturers ....the book is well worth seeking out and reading.
Andy

Out of print, but certainly available. More than two dozen like this one ($8.00 + shipping) are listed for sale at "a popular auction site".

 

[arakboss]

The original rimfires WERE black powder loads. Not sure if the priming compound is the same today though.

It appears from this guy's experience it will work. My thought was to front stuff the loads rather than loading back into the 22lr case. The 22lr case would serve as the breech plug as well as the ignition source.

.22 LR loaded with blackpowder

www.rimfirecentral.com

 

[Capn Jack]

On another less pressure related bp topic: Would the priming compound in a 22lr case be strong enough to light off a load of BP? If so, this could open up a whole new avenue of small bore bp load options.

I believe that rimfire priming compound is very similar, if not the same as percussion caps.

 

[arakboss]

Not a muzzleloader since it loads at the breech but was happy to know toy caps would serve as ignition. I would like to believe that a 22lr case would provide as much or more flame than toy caps?

View: https://youtu.be/cucN0Ny_xp4?feature=shared

 

[dangerranger60]

The 410 load I proposed, should be considered a square load. I could start with less bp and work my way up or less shot and work my way up. I recently acquired a cheap stainless 410 break open and think it would make a good host for trying some stout BP loads.

It would also be a square load if you started with a pound of shot over a pound of BP. but in a small barrel of a 410 the shot would pour out of the barrel nearly at your feet before the powder charge burned half way up its column. once the shot was out of the way you would be holding a roman candle till the rest of the powder burned out. and then you would have a mess of fouling to clean up.

A Square and balanced load would have the powder consumed before the loads is 1/2 out of the barrel. The heat created has the gas still expanding as the load continues out the barrel. you want enough powder so that the gas is still expanding, but not so much that unburned powder is being launched with the load. too much load slows things down, too much powder doesn't allow proper expansion. its a balancing act. DR

 

[arakboss]

View: https://youtu.be/sUnVwFsE3TQ?feature=shared

 

[Andy54Hawken]

Something to consider here...

If...
You were to use a sensible load for your muzzle loading rifle of say something around 20 - 30 grains above the caliber....
As in 80 grains for a .54 caliber rifle , for example....
Then you have a excellent practical load for just about any use and no worries about overloads..or pressure or...whatever else.

While I am not the end all or be all of muzzle loading...I do know a bit about it.
I posted an excellent "sticky " thread about loads for muzzle loading firearms.
The information there has served me well for many years....and I haven't blown up a firearm from using it.
Andy

 

[RVTECH]

Fu Manchu in post # 35 isn't really 'overload testing'.

He is just shoving powder down the barrel of a homemade 'muzzleloader' (out of an unknown section of pipe) for some sort of thrill to see what happens.

There are others like him, doing the SAME thing on YT as well.

 

[Andy54Hawken]

Again...
I don't care what some dumb azz talking head with a You Tube Channel says.

It is dangerous to use smokeless powder in a muzzle loader ...do not do it.

Any more posts , threads , comments , links , etc...suggesting that it is okay / safe to do so...
Will be removed.
Andy