Barrel Ringing

[Col. Batguano]

We all know the importance of firmly seating a ball (or shot charge) on our powder charge with BP. If you don't, the charge will burn, and the pressure from the projectile will reflect it back toward the breech and create a spike in pressure, and potentially ring a barrel. I had a newbie Boy Scout do that to one of my guns one time, so now when ever a newbie is using a gun of mine, I seat the charge after they are done seating it. 9 times out of 10 they don't get it down far enough. Hey, we all start somewhere and have to learn, right?

My question is; that, given the above, why don't smokeless powder cartridges (and guns) suffer from the same thing? Most loaded cartridges are NOT loaded up to being a compressed load, unlike BP loads/

 

[NorthFork]

Cause smokeless is a propellant and BP/Subs are a low grade/brissance explosive. There is a phenomena that is not completely understood that involves very light loads of slow burning powder and large capacity cases that will cause an explosion that usually destroys the firearm.

And before someone calls foul on subs not classified as explosives, it's only because the ignition temp of the subs is high enough for similar transport/storage conditions of smokeless.

Now enough of them thar new fangled cartridge guns. Let's get back to caps and flinters.

 

[Archer 756]

Thats not true the smokless things do have barrles that get ring

 

[Britsmoothy]

Anything that has a barrel obstruction is in trouble no matter what the fuel type is.
Black powder cartridges should not have a cavity too. Some smokeless types should not have a cavity.

When it comes to really high performance and or high pressure modern cartridges the fuel is so progressive a cavity in the case can be tolerated, in fact with some types it is difficult to ignite and any partial ignition itself can creat a partial blockage and a dangerous situation!
Now, I suggest we drop this smokeless stuff before Zonie gets on to us.
4f rocks

 

[EC121]

The Bevel brothers just tested all that short started ball barrel ringing myth. The only way they could get a bulge was to block the barrel with another ball or obstruction, and even then it took a big overload and to do it. A normal load just popped the ball out. After the ball moves any at all the pressure(psi) drops precipitously due to the increasing surface area.. The article was in Muzzle Blasts a while back.

 

[user 43911]

My question is; that, given the above, why don't smokeless powder cartridges (and guns) suffer from the same thing? Most loaded cartridges are NOT loaded up to being a compressed load, unlike BP loads/

In some cases it can be a problem with modern powders, most barrel rings in modern guns are caused by squibs and sending another round behind one, at the point of contact or near to it the air trapped results in a ring being formed, as far as the powder is concerned it's about causing a pressure wave, a compressed load is not needed in black powder and in some cases not wanted, what is needed is contact, this contact and removal of air space does not permit the powder to lay flat only filling half or so of the barrel when held in the firing position , with a tight projectile sealing the barrel if you ignite the powder with a flash over, being ignited front and back at the same time they burn to the middle of the charge causing a detonation/ pressure wave. In some cases the burn rate/pressure increase happens faster than the projectile can get moving. BOOM.

I kept this simple, it can get way more complicated and I don't want to spend the next 4 days going over and over it.

 

[Col. Batguano]

I understand what you're saying mostly, but a touch hole with a liner is by its' very nature going to ignite the powder column somewhat up from the very base of the charge. The way most of us build them that's only going to be about 1/8"-3/16", --not much--but it's still at least somewhat in the middle. Could it be the difference in how the powders burn that makes a difference. BP burns from the outside to inside at a constant burn rate, and nitrocellulose increases the burn rate as pressure increases.

 

[user 43911]

Still closer to the base of the powder charge and not a flash over condition, flash over puts flame at the back of the charge (breech plug) and the front of the charge (projectile) at the same time, take a plastic tube and only fill it half way, now lay it on it's side, the ignition force is normally going to ignite first contact point, skim over, hit projectile and ignite the other end.
A touch hole also vents a little and is why some load data for flintlocks add about 5/10 grains for main charge over percussion (pressure lose).
1/8-3/16 is not in the middle of a main charge of most rifles , when the powder is ignited gas starts being produced moving the balance of the powder down the barrel along with (pushing) the projectile, the tail end of the powder for lack of a better term burns like a bottle rocket driving the projectile out of the barrel, if you put a fuse in the nose of the rocket and into the same powder it's using to fly and lit it at the same time as the back of the rocket it becomes a fire cracker, you have driving gas being produced in two opposing directions to the middle.

 

[user 43911]

BP burns from the outside to inside at a constant burn rate, and nitrocellulose increases the burn rate as pressure increases.

Not correct at all, with the unmentionable powder composition controls burn rate, this is why there is about 50 types ( types, just a number not based on facts). Pressure is based on volume of gas produced for a given space. This is how you figure optimum load, powder has finished burning (creating propulsion gas ) just before the projectile leaves the barrel or velocity required has been reached (within safe limits). If your needs are not met with one powder you change to another faster or slower burn rate to get what you need.
I don't know what to say with regard to burning from out to in. BP Granulation size changes burn rate.

P.S. not really saying I don't know, just, what ?

 

[Okie Hog]

My question is; that, given the above, why don't smokeless powder cartridges (and guns) suffer from the same thing?

With smokeless powder cartridges it's the chamber that is ringed. Problem comes from using smokeless powder charges in large volume cases. The smokeless powder takes up a small volume of the case. Met a shooter who got a ringed chamber using smokeless powder in a .45-90.

Filler packed hard on the powder charge can cause a ringed chamber.

 

[user 43911]

With smokeless powder cartridges it's the chamber that is ringed. Problem comes from using smokeless powder charges in large volume cases. The smokeless powder takes up a small volume of the case. Met a shooter who got a ringed chamber using smokeless powder in a .45-90.

Filler packed hard on the powder charge can cause a ringed chamber.

Ringing in chamber , was this smokeless in a BP cartridge .45-90 ? if so that's a no brainer.

Not in all cases, some powder is sensitive to case volume some are not, the person loading needs to know what they are using.

Not in all cases, some are bulky or not sensitive to volume and again the loader should know what they are using.

What ?

 

[Eterry]

I have a Colt 1917, was carried in WW1. It has 2 barrel bulges, but is shootable.
When I shot pistol competition it was common to see guys who during rapid fire had a squib round then fired a full power load behind it. They almost always got a ring in the barrel, buy most kept shooting.

That can't happen in a muzzleloader, but I've seen a few ringed barrels.

If you want to see the difference between black powder and smokeless just pour out a couple ounces in a straight line then light it.
Even "fast " pistol powder is much slower then black.

 

[user 43911]

Open air burning of powder is not the same has what happens in a confined space, little value in doing this test.
Follow up shot after squib indicates slow S.O.'s
This thread is probably going to close because of unmentionables coming up to much.

 

[Zonie]

The Bevel brothers just tested all that short started ball barrel ringing myth. The only way they could get a bulge was to block the barrel with another ball or obstruction, and even then it took a big overload and to do it. A normal load just popped the ball out. After the ball moves any at all the pressure(psi) drops precipitously due to the increasing surface area.. The article was in Muzzle Blasts a while back.

I was going to mention this but you beat me to it.

For those who haven't read about the Bevel Brothers experiment, they tried everything they could think of to get the barrel to bulge. They tried this with several barrels.
As long as they loaded only one ball, none of their powder charges did any damage to the barrel at all. They loaded the ball just a few inches above the black powder charge and they loaded the ball just a few inches below the face of the muzzle over small BP charges and over huge BP charged. Nothing bad happened as long as they were loading only one ball.

It was only when they rammed a ball down on top of the powder load like one does when they correctly load a barrel and then rammed another ball, part way down the barrel that they managed to damage the barrel. When they loaded the barrel with the two balls spaced apart, the barrel was bulged where the upper ball was located. As memory serves me, the end of the smoothbore barrel totally blew apart where the upper ball was located.

 

[user 43911]

Just goes to show that a black powder load does not need to be seated, a multi decades old wife's tail bites the dust. Manufacturers should update their owners manuals also and again shows that miss information can go a long way and become ingrained as fact.

 

[user 43911]

and potentially ring a barrel. loads/

Back to the beginning, It's a crud ring
Black powder will do that well. All solved end of thread.

 

[hanshi]

We all know the importance of firmly seating a ball (or shot charge) on our powder charge with BP. If you don't, the charge will burn, and the pressure from the projectile will reflect it back toward the breech and create a spike in pressure, and potentially ring a barrel. I had a newbie Boy Scout do that to one of my guns one time, so now when ever a newbie is using a gun of mine, I seat the charge after they are done seating it. 9 times out of 10 they don't get it down far enough. Hey, we all start somewhere and have to learn, right?

My question is; that, given the above, why don't smokeless powder cartridges (and guns) suffer from the same thing? Most loaded cartridges are NOT loaded up to being a compressed load, unlike BP loads/

Any obstruction in the bore of a rifle, BP or smokeless, will do that. Also smokeless is a "progressive burn" powder and has to build quite a bit of pressure just to get the projectile moving and the charge combusted.

 

[Col. Batguano]

Ok so I have a slightly loose spot slightly forward of where a ball sits / seats in my flint 40 cal Lancaster. Not enough to measure from the outside, but you can feel it with a patch. It didn't exist before I started teaching the Boy Scouts about ML'ers. Our charges were only 30-40 gr. FFFg. We never double loaded. How else could it have gotten there except for a non-fully seated ball?

 

[Zonie]

Ok so I have a slightly loose spot slightly forward of where a ball sits / seats in my flint 40 cal Lancaster. Not enough to measure from the outside, but you can feel it with a patch. It didn't exist before I started teaching the Boy Scouts about ML'ers. Our charges were only 30-40 gr. FFFg. We never double loaded. How else could it have gotten there except for a non-fully seated ball?

Someone could have dropped a bare ball down the bore without your knowing about it. If the ball fell down the bore and stopped a few inches in front of the rammed ball, that could bulge the barrel exactly like you say it is.

 

[EC121]

It doesn't take much pressure to get a ball moving. CO2 ball extractors and even air compressors do it with an O-ring seal. If a ball could be stuck tight enough to ring a bore, you would have to have a hydraulic rammer to push it down. You also wouldn't be able to pull a ball by hand. I'd almost bet that 30-40grns. would exhaust out the touch hole of a fully plugged barrel before it harmed the barrel.