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Old July 16, 2013, 09:16 AM   #26
Hawg Haggen
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Quote:
I do think you could glue a paper tube to the ring second up from the bottom on the projectile you pictured without it breaking off from the tube. Perhaps even higher up since you said the projectile went into the barrel's rifling only up to the topmost first ring. That leaves you all the other rings to glue to, even if you don't glue to the very bottom of the projectile.
Therein lies the problem. Finding something to form the cartridge paper around that is the same size as the bottom ring. I tried forming one a little bigger than the bullet but it came out too big to fully load into the chamber and the powder bunched up. For best results you need a hollow tube that the base of the bullet fits into snugly and is the same size as the bottom ring (the other two rings are smaller) so you can roll the paper around the bullet and the form together. It is exceedingly difficult to try to roll a cartridge around just the bullet and keep it anywhere near concentric.



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I'll find the research myself. If your research only consisted of people at forums writing, it probably didn't get into the precise lab science explanations I was seeking anyway to determine if it causes any overpressure safety concerns with heavy charges. Although sometimes there are some bonifide lab scientific results pressure scale data that is posted at online forums.

Good luck. In several months of searching I didn't find anything like that but maybe your google fu is better than mine.
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Old July 16, 2013, 09:49 AM   #27
Bill Akins
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I understand. Perhaps if you could find a dowel that is the same size as the diameter of the bullet just below the bottom most ring, or maybe you could lathe out a dowel to the correct diameter. Maybe then you could put a tiny dab of fingernail polish or glue on the outer diameter of the base and then just roll the cartridge around the bullet like a cigarette paper is rolled around a filter, and so that the tube would be flush with the diameter of the bullet's base diameter and not as large as one of the rings that engages the rifling and then carry that paper cartridge flat in your cartridge pouch so there isn't any pressure on the projectile to break loose from the paper. Have you tried that yet?

Several reasons I am interested in data regarding air space behind the powder charge and projectile possibly causing overpressure safety problems is this.....

Quite often when I reload cases with smokeless or black powder, I don't load them that full to where the powder is right up against the bottom of the projectile's base when I seat and crimp the projectile. So when the cartridge lays in the chamber, the powder can lay down somewhat horizontally (if I am shooting fairly horizontally) and there would be an air space over the top of the powder behind the projectile or the air space could also be directly behind the powder if one were shooting downward, say at a snake. But that has never caused a problem. This is true of factory loaded ammo also. So if air spaces behind the projectile are supposed to be avoided due to possible overpressure problems, what about the air space in a cartridge that doesn't have its powder charge firmly up against the bottom of the projectile's base?
Something I have always wondered about.

Also in muzzleloaders we are taught that a projectile should always be seated firmly against the powder charge or it can cause an overpressure that could bulge or blow the cylinder or barrel. In a standard muzzleloading rifle, if the ball were to be much forward of the charge, creating an air space between the powder and the projectile, that can and has resulted in a bulge or blown barrel due to overpressure, so we know that to be a fact. So what is confusing is why doesn't that happen when a cartridge case isn't loaded to full capacity and the powder isn't right up against the projectile's base?

In the case of your Sharps, said air space is only BEHIND the powder when your barrel is pointed downward. But once you raise your Sharps to a horizontal position, the loose powder in the chamber levels out so that there is an air space over the TOP of the powder and also BEHIND the projectile say around half the diameter of the base of the projectile, just like in a cartridge that was not loaded to full powder capacity and was firing horizontally.

So there is a difference in where the air space is in that instance since it can either be over the top of the powder if shooting relatively horizontally, or behind the powder (if shooting downward). What I would like to know is if there data that shows any difference in relation to overpressure with an air space BEHIND the powder charge, or air space over the top of the powder and thus air space behind say half of the base of the projectile.

And if there isn't any overpressure concern with an air space laying over the top of the powder horizontally, and thus that would mean there was an air space over say half of the rear of the projectile, then if that doesn't cause an overpressure problem, then why does data teach us that an overpressure problem occurs if there is an air space between the powder and the projectile?

I'd like to find out the answer to these questions since a partially loaded cartridge case and the way your Sharps loads, would seem at first review, that it should cause an overpressure problem and I wonder why it doesn't or if it does and if it's just not that critical for some reason to where it doesn't cause bulging or blowing up of the barrel or chamber.

Even though your Sharps has some pressure release because of the thin line of space between your chamber and the breech block that could relieve some overpressure, just as the barrel to cylinder gap of a revolver could do, is that enough of a pressure release mechanism to prevent a bulged or blown barrel? And that still doesn't account for the same situation in a totally sealed breech autoloader with no pressure release that could lead to a blown off case rear.

So considering all that above, I wonder why it would seem that sometimes air spaces either between the powder and projectile, or just behind the powder, or on top of the powder and behind at least half the base of the projectile, do not cause the same overpressure problems that we are taught happens if we do not take care to seat the projectile completely against the powder in our smoke poles.

Interesting pressure questions that I have never seen the info/data that answered them for me.


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"This is my Remy and this is my Colt. Remy loads easy and topstrap strong, Colt balances better and never feels wrong. A repro black powder revolver gun, they smoke and shoot lead and give me much fun. I can't figure out which one I like better, they're both fine revolvers that fit in my leather".
"To be sure of hitting the target, shoot first and call whatever you hit the target".

Last edited by Bill Akins; July 16, 2013 at 10:22 AM.
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Old July 16, 2013, 10:30 AM   #28
Hawg Haggen
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I cant answer those questions. I've always loaded my bp cartridges with no airspace. I would assume that with pistol size cartridges and a reasonable load the airspace would be minimal and any over pressure would be negligible. If you load a muzzle loading rifle and leave an airspace the powder will still level off so the space is over the powder. The difference being the muzzleloader only has the nipple to vent the pressure and the bore size is the same as the ball. The Sharp's chamber is oversize and the breech is an imperfect seal even on originals and guns with a sliding chamber. I did wonder why the chamber was so much bigger than the bullet. Maybe that has something to do with it.
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Old July 16, 2013, 10:45 AM   #29
Bill Akins
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Perhaps the answer is simply that a small amount of air space either only behind the powder itself, or over the powder and behind the projectile, or even BETWEEN the powder and the projectile, is not critical because the expanding gases quickly fills that small air space BEFORE any dangerous overpressure could occur. If so, that doesn't explain why we have always been admonished by the firearm scientists and manuals that we MUST fully seat the projectile against the powder charge in our smoke poles.

Unless they knew this and were just preaching to the lowest common sense denominator (and for liability purposes too) so that someone wouldn't foolishly load their ball only halfway down the barrel to where it WOULD become a problem since the gases had largely expanded and reached high pressure by the time they hit the projectile and thus it would act as an obstruction. Could it be that simple? If so, then the firearm scientists and firearm manuals have actually been preaching wrong to us just to make sure someone doesn't foolishly load their ball halfway down the barrel. Could that be it? Could it be that simple?



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__________________
"This is my Remy and this is my Colt. Remy loads easy and topstrap strong, Colt balances better and never feels wrong. A repro black powder revolver gun, they smoke and shoot lead and give me much fun. I can't figure out which one I like better, they're both fine revolvers that fit in my leather".
"To be sure of hitting the target, shoot first and call whatever you hit the target".
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Old July 16, 2013, 11:09 AM   #30
Hawg Haggen
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It very well could be but I'm not going to try it to find out.
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Old July 16, 2013, 08:16 PM   #31
sltm1
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Hawg, why not get a dowel (turn one down if oversized) the same size as the bottom band of the slug, (not the tail, full diameter). You could drill a hole in the end of the dowel to accept the tail and that way hold both pieces together while gluing both the seam and the paper to the bottom ring of the slug?
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Old July 16, 2013, 08:23 PM   #32
Hawg Haggen
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I thought about that. It would have to be 5/8 dowel tho. 1/2 is too small. Gonna have to wait until I go back to work. Money is too tight right now to buy one.
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