Why does smokeless powder peel open a muzzleloader like a banana?

[bronko220002]

The major difference is that black powder burns where as smokeless detonates. This causes smokeless to reach peak pressure at a much faster rate. Now another thing that USED to be is that barrels for black powder firearms didn't go through the same testing as barrels that used smokeless. This was because of the lower pressures involved. I don't know what kind of testing is required these days. I'm thinking its a little more stringent now.

 

[French Colonial]

The major difference is that black powder burns where as smokeless detonates. This causes smokeless to reach peak pressure at a much faster rate. Now another thing that USED to be is that barrels for black powder firearms didn't go through the same testing as barrels that used smokeless. This was because of the lower pressures involved. I don't know what kind of testing is required these days. I'm thinking its a little more stringent now.

Not true, smokeless burns albeit at much faster rates and it develops much higher pressures.
Once again, google is your friend, google burn rates for smokeless powder.

https://loaddata.com/Article/BurnRateCharts/Powder-Burn-Rate-Chart-NEW/159

 

[oldwood]

Back in the 1970's , a well known gun barrel maker said , modern cartridge powders have a high sharp initial pressure spike . The soft lead bearing (free machining) steel , used for m/l gun barrels , isn't designed for that pressure spike. The lead bearing steel , more closely resembles iron in ductility. Black powder doesn't exhibit that type abrupt pressure spike , so is correct for m/l use.

 

[TFoley]

Here in UK we have two gunsmiths who produce nitro propellant, front-loading conversions to well-known handguns, namely the Colt SAA and a more modern style that looks a lot like a Smith & Wesson Model 27. Look up Alan Westlake and Alpha firearms on Youtube to see what a total PITA is is to carry out the loading and so on.

In both cases, the actual load of propellant, regulated by the space available, is not more than around 4gr of a suitable propellant. This is quite sufficient to launch the .38cal wadcutter at a respectable velocity suited to target shooting at 25m or less. Priming is by #209 shotgun primers.

The cost of these things is prodigious, to say the least - around $800-900. Of course, you can't have a handgun that you already own converted in this way, since 1997, that is. And if you are lucky enough to live in Northern Ireland, where you CAN have the handgun in its original format - shooting a metallic cartridge - there is zero 'need' to do it anyhow.

All it does for us here on Mainland GB is allow us to shoot a revolver that still looks like an ordinary revolver, and not something out of a Star Wars movie.

 

[Loyalist Dave]

I've seen modern barrels with modern ammo split like a banana, due to a muzzle obstruction. I've seen many BP barrels bulged or bulged and split, due to BP pressure exceeding the tensile strength of the barrel, but with BP they didn't "shatter", and I think this was due to the pressure reducing, either because the obstruction began to move toward the muzzle and thus the pressure dropped, or the barrel started to split, venting pressure and halted the process.

With the modern powder the pressure exceeds the tensile strength of the barrel steel so fast, and the steel used for BP barrels then ruptures into fragments and shatters. When I see a BP barrel with chunks blown out at or near the breech, I immediately think "smokeless".

LD

 

[bronko220002]

Not true, smokeless burns albeit at much faster rates and it develops much higher pressures.
Once again, google is your friend, google burn rates for smokeless powder.

https://loaddata.com/Article/BurnRateCharts/Powder-Burn-Rate-Chart-NEW/159

Check this out (actually at the end of the article in the summary) this is where I got my info on Google.
https://www.thefirearmblog.com/blog/2016/11/02/black-vs-smokeless-powder/
Both BP and smokeless burn at reltively the same rate when unconfined. BP burns at the same rate unconfined or confined where smokeless burns at a faster rate when confined because it generates more gases to increase burn speed and it doesn't need oxygen to burn. As it continues to burn (confined like in a barrel) because it continues to burn faster it creates more and more pressure until the bullet exits the muzzle and it is no longer confined. That is the reason barrels blow up. Smokeless is 3 more powerful than BP when confined.

 

[Col. Batguano]

This is going to be mostly anecdotal, but perhaps it bears some relevance. My experience when burning loose piles or lines of both black and smokeless powders is that the BP burns much faster and seemingly more energetically. The research would suggest that this burn rate is the same if it is loose or if it is confined, while smokeless is the opposite.

They load artillery shells (and coat the bottom of powder bags with real BP for the really big stuff like battleship guns) with a primer (about the size of a 50 BMG) inside a small case (about the size of a 38 Special for a 37mm) which is filled with real BP. That case sits in the traditional place a primer normally does. Sort of a primer within a primer. The primer ignites the BP, and the BP ignites the main charge. That would suggest that the BP is needed to magnify the fire from the primer to expand out in to the main smokeless powder charge, and get enough of it burning fast enough to allow shorter length barrels. That system of making artillery shells starts at about the size of a 37mm, and goes up from there. Below that (25mm and 20mm) only the 50 BMG primer is used.

They also used BP as the main charge in the WW II era "pineapple" hand grenades. Not sure what they use in the more modern "baseball" shaped ones. Perhaps they use real BP as a starter charge?

 

[hanshi]

PRESSURE WAY ABOVE BP LEVELS FOR USE IN MUZZLELOADERS.

 

[Felix the Cat]

This is going to be mostly anecdotal, but perhaps it bears some relevance. My experience when burning loose piles or lines of both black and smokeless powders is that the BP burns much faster and seemingly more energetically. The research would suggest that this burn rate is the same if it is loose or if it is confined, while smokeless is the opposite.

They load artillery shells (and coat the bottom of powder bags with real BP for the really big stuff like battleship guns) with a primer (about the size of a 50 BMG) inside a small case (about the size of a 38 Special for a 37mm) which is filled with real BP. That case sits in the traditional pllaceThe primer ignites the BP, and the BP ignites the main charge. That would suggest that the BP is needed to magnify the fire from the primer to expand out in to the main smokeless powder charge, and get enough of it burning fast enough to allow shorter length barrels. That system of making artillery shells starts at about the size of a 37mm, and goes up from there. Below that (25mm and 20mm) only the 50 BMG primer is used.

They also used BP as the main charge in the WW II era "pineapple" hand grenades. Not sure what they use in the more modern "baseball" shaped ones. Perhaps they use real BP as a starter charge?

Nearly right..!

What you say about BP igniters for Artillery is correct, although the latest designs are moving away from BP as an igniter. The problem with Artillery Propellent is that there are lots of voids in the cartridge space, particularly in designs where there are variable charges, and the need is to ignite the whole surface of the propellant as quickly as possible. BP primers fill the chamber almost instantly with flame regardless of how much space there is. The 175 howitzer had a huge long and relativly thin chamber, so the charge bag had a long polythene tube filled with BP up the centre to ensure it all got lit.

The pre ww2 Mk2 Grenade was initially filled with smokeless EC powder not GP. The idea was that it would give better fragmentation with the cast iron body than HE. It had an igniferous time fuse but was replaced with an HE filled version (usually TNT) early in the war. The HE version had a detonating time fuze and was initially painted yellow. The original T-13 "Beano" baseball grenade was filled with TNT and had an impact detonating fuze. The more common M67 "baseball" grenade had a time fuze, which contained GP and had a "Composition B" (RDX./TNT) filling.

...but we are really straying way out of the subject area, so I think we should stop here!

 

[Felix the Cat]

Check this out (actually at the end of the article in the summary) this is where I got my info on Google.
https://www.thefirearmblog.com/blog/2016/11/02/black-vs-smokeless-powder/
Both BP and smokeless burn at reltively the same rate when unconfined. BP burns at the same rate unconfined or confined where smokeless burns at a faster rate when confined because it generates more gases to increase burn speed and it doesn't need oxygen to burn. As it continues to burn (confined like in a barrel) because it continues to burn faster it creates more and more pressure until the bullet exits the muzzle and it is no longer confined. That is the reason barrels blow up. Smokeless is 3 more powerful than BP when confined.

Although the firarms blog is correct in that Black Powder is less affected by pressure than smokeless this is a huge oversimplification.. The statement that Black Powder burns whilst nitro detonates is 100% wrong when applied to propellent. Def;lagration and detonation are two entirely different physical and chemical effects. It is considered impossible to detonate Black Powder, and although it is possible to get nitro powders to detonate, this should never occur when they are being used as a propellent.

Where I do agree with your statement is that the energy potential in smokeless powder is orders of magnitude greater than black powder and it has to be handled in a completely different way. It is possible to create BP substitutes such as Pyrodex, but they are not the same formulations as traditional nitro powder

 

[bronko220002]

Although the firarms blog is correct in that Black Powder is less affected by pressure than smokeless this is a huge oversimplification.. The statement that Black Powder burns whilst nitro detonates is 100% wrong when applied to propellent. Def;lagration and detonation are two entirely different physical and chemical effects. It is considered impossible to detonate Black Powder, and although it is possible to get nitro powders to detonate, this should never occur when they are being used as a propellent.

Where I do agree with your statement is that the energy potential in smokeless powder is orders of magnitude greater than black powder and it has to be handled in a completely different way. It is possible to create BP substitutes such as Pyrodex, but they are not the same formulations as traditional nitro powder

Curious Felix. Where did you get your info. Link please.

 

[Felix the Cat]

Curious Felix. Where did you get your info. Link please.

30+ years in the ammunition business!

..not everything is available on the internet! Happy to address any specific issues you want to put, but there is no "definative" work that I am aware of on line. Most of the reference works are classified government research documents and are not on open publication. There is some interesting material in the British "Handbook of Ammunition" and "Treatise on Ammuntion" editions of which are available up to the end of WW2 and can be found on line. Col Chinn's books on "The Machine Gun" also have some information on ballistics and gun design that are worth looking at.

There is also a three volume book on Explosives by Marshall that has a good description of Gunpowder and Smokeless propellent use and manufacture during WW1 but is hard to find (I have a hard copy!)

For US ammuntion, most of the TM (technical manual) series is available on line, although this is pretty much directed at equipment rather than theory.

... I suppose that those "in the know" have neither the need nor the wish to promulgate this type of knowledge in the general population! I wonder why?

 

[springfield art]

People simply seem to want modern gun performance from a muzzleloader and out of this world performance from a bow. I don’t get it. Folks are shooting non-trad black powder guns and crossbows in what were once primitive deer seasons. This tells me they don’t embrace either hunting with muzzleloaders as our ancestors did or archery as it was practiced until the 1940s. They don’t want the limitations of primitive weapons. Might as well have a single shot deer season where any single shot gun is allowed.

On the topic of smokeless powder in a muzzleloader it’s been covered.
1) the steels that have always been safe for BP are not safe for reasonable loads of smokeless.
2) unlike cartridges which cannot be insanely overloaded because of volume restrictions, a ML barrel will hold a lot of powder.
3) if someone DOES make a ML from 4140 and it is safe for reasonable loads of smokeless powder, those ignorant of the issues will say that Bob uses smokeless in his ML gun, no problems, so I’m gonna use it in mine. THINK OF OTHERS. THINK OF UNINTENDED CONSEQUENCES.

Speaking of Crossbows; my pal, a combat vet of Vietnam, showed me after-action photos of a typical infantry engagement around 1970. The crossbow that the enemy had, was used to shoot MONKEYS for food! Not only were the enemy shod in sandals made of old tires, but they were eating wild game! You simply cannot defeat an enemy that dedicated, comfortable in the jungle, and motivated by an over-arching theology such as communism!

 

[Rifleman1776]

Is the issue the metal ML’s are made of?

Yes. And, it is my understanding the difference between ml barrel steels and GBQS for modern guns using smokeless powders is deliberate for safety sake. If over pressured with GBQS those barrels would shatter like a grenade. But, ml barrels relieve the excess pressure by splitting.

 

[webb116054]

You can shoot a ML with smokeless powder at least one time, but I would make sure that you had the ambulance on stand by, because you will basicly be trying to shoot a pipe bomb ! Smokeless powder creates higher chamber pressure than black powder or imitation black powder ! I saw a man loading a Pietta 1858 Remington steel frame revolver with unique smokeless powder . He was using 7 grains of powder with a 44 caliber round ball . I warned him that the cylinder could not withstand the pressure that smokeless powder created . He told me he had been doing it for years and other people used smokeless powder in their Ruger old army revolvers all the time ! I tried to explain to him that the ruger revolvers and cylinders were made to take the pressure of smokeless powder in light loads. The man basically told me to mind my business, so I just walked on down the line and started shooting my pistols . Then, after 4 shots, I heard a loud bang and heard metal hitting the roof of the firing line stations and the side of the concrete block wall and I saw a big flash of fire, and heard a scream ! I looked up the line and saw the man that was shooting the smokeless powder in his black powder only revolver, standing there with a bloody hand and face , holding what was left of his pistol! The cylinder had blown up like a grenade and sent steel fragments in the mans face, neck and right arm and had split the barrel open where it goes into the frame , which looked like King Kong had ripped it apart ! The man was very lucky because he only got a few stitches in his face, hand and neck and trigger finger that was busted open ! No other shooters were injured because they had moved away from the man like I did ! You might get away with shooting smokeless powder in a black powder only firearm for a while, but sooner or later, your pipe bomb is going to explode and possibly hurt you or s bystander !

 

[sussexmuzllodr]

Lather rinse and repeat.

 

[springfield art]

I crossed paths with a video on this forum, can’t remember where, that demonstrated what happens with smokeless powder. Scary! It blew up every ML it was loaded in! I thought it was a bit of an over charge at 150 grains, but with BP I think the barrels would have survived? Is the issue the metal ML’s are made of? Barrel Wall thickness? How can a cheap black gun pop off smokeless forever and an expensive BP barrel becomes a cautionary tale? I don’t want to shoot the stuff, just curious.

The modern powder expands almost totally at once whereas the black powder "pushes" more smoothly, something like that! Someone on here will describe it better; I'm sure there's lots on line about that, it's good that people are aware; most muzzle loaders are marked' black powder only'.

 

[springfield art]

You can shoot a ML with smokeless powder at least one time, but I would make sure that you had the ambulance on stand by, because you will basicly be trying to shoot a pipe bomb ! Smokeless powder creates higher chamber pressure than black powder or imitation black powder ! I saw a man loading a Pietta 1858 Remington steel frame revolver with unique smokeless powder . He was using 7 grains of powder with a 44 caliber round ball . I warned him that the cylinder could not withstand the pressure that smokeless powder created . He told me he had been doing it for years and other people used smokeless powder in their Ruger old army revolvers all the time ! I tried to explain to him that the ruger revolvers and cylinders were made to take the pressure of smokeless powder in light loads. The man basically told me to mind my business, so I just walked on down the line and started shooting my pistols . Then, after 4 shots, I heard a loud bang and heard metal hitting the roof of the firing line stations and the side of the concrete block wall and I saw a big flash of fire, and heard a scream ! I looked up the line and saw the man that was shooting the smokeless powder in his black powder only revolver, standing there with a bloody hand and face , holding what was left of his pistol! The cylinder had blown up like a grenade and sent steel fragments in the mans face, neck and right arm and had split the barrel open where it goes into the frame , which looked like King Kong had ripped it apart ! The man was very lucky because he only got a few stitches in his face, hand and neck and trigger finger that was busted open ! No other shooters were injured because they had moved away from the man like I did ! You might get away with shooting smokeless powder in a black powder only firearm for a while, but sooner or later, your pipe bomb is going to explode and possibly hurt you or s bystander !

Good post; interesting; I guess he shut up after that!

 

[bronko220002]

What I thought I read is that black powder burns at a constant rate either open or confined whereas smokeless powder when confined burns faster the longer its confined and the faster the burn the more pressure is generated. Also smokeless does not need oxygen to burn where black does.

 

[deerstalkert]

What I thought I read is that black powder burns at a constant rate either open or confined whereas smokeless powder when confined burns faster the longer its confined and the faster the burn the more pressure is generated. Also smokeless does not need oxygen to burn where black does.

both types of powder contain oxidizers, in the case of black powder it is potassium nitrate. no external O2 is required.
pressure graph of Bp.

smokeless compared to BP