I have a buddy who is a disabled former machinist. He has been slowly building a model Parrott field rifle for at least the last 10 years. The design was published in an early "Home Shop Machinist". He does beautiful work. This year he got it done enough to fire it for July 4th. It worked fine, but he was greatly disappointed in how loud it was, or wasn't.
Now I'm wondering what if anything he could do to make it louder. Is there louder powder? What if he increased the bore from 5/8" to 3/4"? Anyone?
========= Somewhere back in my misspent youth I remember reading that adding fine iron powder to the black powder increased both the flash and bang of firecrackers. Cheap enough to try out.
Powdered aluminium is an explosive and may work the same way.
If you do this please use a looong string for test firing.
Unka' George [George McDuffee] ============ Merchants have no country. The mere spot they stand on does not constitute so strong an attachment as that from which they draw their gains.
Thomas Jefferson (1743-1826), U.S. president. Letter, 17 March 1814.
DO NOT TELL ANYONE ABOUT THIS, OR I WILL HAVE TO KILL YOU! ........................
As we speak, I am working on two devices. One is a gopher killing device that uses 5% propane and 95% pure oxygen underground to make a concussion to kill the gophers.
And while I am at it, I have decided to make a noisemaker that will give my peaceful valley a good bang next Fourth of July. I am thinking about a 8' length of 8" schedule 40 pipe with the bottom capped. The top would be open, and pointed up. Masking tape would close the top, save for a small pressure relief hole punched in it and a flap of paper to keep the gases in. It would have a remote sparker. It would have flashback arrestors on the inflow ports.
Propane and oxygen would be forced into the pipe for a couple of minutes. All flow lines would be removed. From a safe distance and with ear protection in place, boom.
We did something similar one 4th with a 55 gallon barrel, some gasoline, some oxygen, and a spark plug. We blew out some windows in our house, lessened our hearing for a couple of days, and had most of the police department and fire department out there.
But all we could say when they asked questions was, "huh?"
Luckily, we had time to clean up the pieces we could find before they got there.
It was loud, and the fireball was awesome.
How do we ever survive our childhoods, no matter how lengthy?
Might could also be because of tight tolerances? Ie, *all* the expanding gases (and sound) are propelling the ball, as opposed to some side escape, etc.? ie, too well made? :)
No, it is not. Trust me on this one... I have a little experience in the field. It can increase the muzzle flash and the bang, but it is not an explosive, it is a combustible fuel. Properly dispersed in air, it can form an explosive mixture, as can any combustible fine dust. Added to black powder, however, it can dangerously increase the combustion temperature - and thus the reaction rate - of the powder, and damage the gun.
Were I trying to help Grant's friend, I'd ask a few questions, first.
1) how is the rifle fired? Percussion cap? increasing the penetration of the cap's fire into the charge will increase the speed at which pressure rises in the chamber.
2) is the charge "stemmed" ? (is the barrel obturated by some sort of plug, like a one or two calibre load of flour, or a projectile?)
3) What is the grade of powder. Finer particles burn faster, within some fairly broad limits.
4) Is the load anywhere near the maximum safe load for the gun? Getting as much still-expanding gasses out the muzzle as possible is important to getting noise and flash.
Within the limits of safety for the barrel design, I'd use a larger cap, shorter nipple, finer powder, a larger load, and stemming.
You needn't seal the muzzle. There are several commercial "concussion guns" available to pyrotechnicians that use propane/oxygen and standard gas valving to meter a charge (usually under PLC control) JUST before firing. Some can fire as frequently as once every half-second.
Never fire modern nitrocellulose powders in a weapon designed for black powder.
Pyrodex is listed as a "smokeless propellant", but it is basically a jinked-up re-formulation of black powder designed to work volume-for-volume the same as BP.
Nitrocellulose powders can detonate. Double-based NC powder (containing nitroglycerine) very likely will detonate if not loaded precisely correctly.
Nobody has asked, and it was not offered if this gun was built to a specific design (with specified alloys) that was proofed by the original designer. Although it could be expensive to have the barrel proofed, it would certainly be nice to know what the design's original proof load was.
I believe that powder is ladled into the back of the barrel, rammed, then wadding is inserted. A fuse is inserted down the vent to fire the piece.
So far just wadding.
I believe FFG.
I don't know, nor do I believe the maker knows, the grade of stainless he used for the barrel. To me it looks completely overbuilt, but I have a lot of respect for black powder.
He can certainly try finer powder and a slightly larger load, but firing projectiles is going to be problematic as he lives in a large city.
If he can find a bore-size cardboard tube; place within it a plastic pouch filled with a weighed amount of water, sealed and held against the back of the tube with cereal filler, seal the forward end of the tube and back the tube with an obturating (bore sealing) over-powder wad; he can simulate the mass of a projectile and exhaust only a cloud of steam and confetti from the muzzle. I've seen something similar done with full propellant charges in an
81mm mortar, at an arsenal in an urban environment (long before 'Homeland Security' became an issue). He should perfect this technique first at a safe firing range and ascertain the range and spread of the ejecta.
I did some playing with model cannons years ago, and never made one make an impressive noise without using a properly patched projectile. Just a powder charge and a wad will not produce more than a thump. Naturally, a properly patched projectile propelled by a significant powder charge fired from a very inaccurate cannon is a bad idea in your average back yard. I gave up when I accidently shot a hole in something expensive.
Reminds me of the one I made when I was a kid. I went to the library and found a picture of a revolutionary war cannon and scaled it down and drew a print of it. I machined it from the print and since the only long drill I could find was a .25 inch.. that was the caliber. One of the first times I shot it was in our basement. I put up some cardboard and wood and aimed it at the target. It missed the wood, went right through 10 layers of cardboard, hit the piano seat rung and went through it and then bored itself into the piano never to be seen again. That sucker was real hard to aim......
The old "Big Bang" cannons used just acetylene (from calcium carbide + water) in air, open muzzle. The large ones make a pretty good noise.
8 feet of 8 inch pipe would be considerably larger and louder. Now, if you reduced that 8" pipe to, say, a 3" barrel you'd have one hell of a potato cannon....
Don't know for a certainty but confinement (as by a projectile mass) is essential for building up pressure and complete burning of a propellant so I would expect it to be louder than firing with just wadding. (I never personally had occasion to fire a gun with just wadding). Unburned propellant contributes nothing to the quantity or pressure of the bore gasses.
The purpose of the water filled tube is to provide projectile mass without resulting in the ejection of a solid projectile from the muzzle. When I saw this done it was for the purpose of simulating normal recoil. The cardboard tubes that the mortar shell came packed in were attached to the fin assembly (needed to hold the propellant charges) then filled with water to match the total weight of the mortar projectile. Fin assembly flew a few tens of yards; big cloud of steam. It was a long time ago but IIRC it was of more-or-less normal perceived loudness. Neighboring houses were about 100 yards away (most of these families probably worked at the arsenal).
"stemming" is not a "projectile". It's a frangible plug made of a package of dust. It has mass, thus allowing chamber pressure to grow before it moves, but it is not solid; it simply disintegrates upon leaving the barrel.
Reenactors often use common wheat flour wrapped in thin paper or thin aluminum foil. About two barrel i.d. in length (two calibres).
Thanx, to Lloyd: His insightful and accurate post answered all questions posed in the OP. Others would do well to carefully read Lloyd's post on this and other "explosive" subjects as they come up. Lloyd is a fireworks professional.
With a 5/8" bore and a reasonable pressure, .....should be plenty loud. What was his load? What powder? What kind of wad?
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