handgonne material

[Leonredbeard]

Thanks, Claypipe.
I understand what you said. Now, perhaps my machinist friend was wrong about the type of brass he ordered. He was working from memory. this brass is quite malleable. I had made some hachsaw cuts a tenth inch too deep for the profile. So I cut some thin strips from the slabs I had cut off. I peened them into the sawcuts to the point that they pretty much disappeared when I filed them. This stuff is not brittle by that experience. Even so, I will keep the loads on the light side, where pressures listed in tables are below the yield pressure. That way there will be an absolute minimum of flexing over time. I likely won't shoot it that much anyway, just to demonstrate to others. And I will warn them to stand behind me.
volatpluvia

 

[Renaman]

How about a bore liner?

Mark

 

[pondoro]

Is it practical with a very malleable material to measure the bore after every 10 shots or so and ensure it is not growing? I am not proposing this as an alternative to using the right material in the first place, but if it deforms significantly prior to failure then a plug gauge in the bore or a micrometer on the outside might show the growth.

My industrial experience is with brittle materials that fail after almost no deformation.

 

Is it practical with a very malleable material to measure the bore after every 10 shots or so and ensure it is not growing? I am not proposing this as an alternative to using the right material in the first place, but if it deforms significantly prior to failure then a plug gauge in the bore or a micrometer on the outside might show the growth.

My industrial experience is with brittle materials that fail after almost no deformation.

That would seem a good idea. However, in many cases of metal fatigue, no measurable deformation occurred before failure. So there lies the rub. The Tannenberg has a reinforced muzzle and powder chamber area. If it were to deform, I would hazard to say that it would be with in one and a half inches of the bore after the end of the powder chamber area. On my website, from a test project on another forum, I have a page where I tried to get one made from 12L14 to fail using multiple ball loads and air pockets in the powder chamber. That piece came through with no deformation.

CP

 

Sorry if it seems I am beating a dead horse here. But, I feel you can't go overboard illustrating the need for the use of proper material for making either gonnes and cannons.

This is a cannon failure from a Snohomish, Washington, high school football game that resulted in serious injuries.

Police sought assistance from the Bureau of Alcohol, Tobacco, Firearms and Explosives in determining why the cannon blew up. The federal agency has not issued a written report but told police there "were problems with the metallurgy of the cannon," Turner said.

The cannon was built by students in the school's metal shop after a previous version gave out in the 1980s.

Karch had helped roll it to the field. He and two other cadets packed the barrel with about 5 ounces of gunpowder. There was a 10-second countdown and Karch pulled the trigger.

The preceeding quote came from here:[url] http://www.columbian.com/news/state/APStories/AP06012007news147867.cfm[/url]

 

[Deadeye]

http://img.photobucket.com/albums/v117/8225hy/TheBeast-Handgonne.jpg
For this ugly handgonne, I used a piece of 12 ga.
shotgun barrel which I think is strong enough for the loads I use but to be on the safe side I machined a powder chamber into an insert of tool steel so that now I have 1/4" sidewalls on the powder chamber. A lot stronger than just the barrel itself. It ain't purty but it's a shooter.

 

[Deadeye]

I remember reading about the cannon explosion when it happened and I thought then and still think that the powder was smokeless or a mixture.
Amazing how many people don't know the difference.
Local guy borrows a muzzleloader, loads it with smokeless, blows it up, no injury, borrows another
loads it with smokeless, lets a friend have the first shot, friend gets a nipple in his forehead,
lives but right eye not very good. He had used pyrodex so bought a can of green dot because the can looked similar. " Black powder only" doesn't tell you much when almost all powder is black.

 

http://img.photobucket.com/albums/v117/8225hy/TheBeast-Handgonne.jpg
For this ugly handgonne, I used a piece of 12 ga.
shotgun barrel which I think is strong enough for the loads I use but to be on the safe side I machined a powder chamber into an insert of tool steel so that now I have 1/4" sidewalls on the powder chamber. A lot stronger than just the barrel itself. It ain't purty but it's a shooter.

Good looking piece. Though the flash guard isn't really period. Was that one of those parker barrels that Numrich was selling? What sort of steel did you use to breech it? Just looking at the photo, one can see that they are two different grades.

CP

 

I remember reading about the cannon explosion when it happened and I thought then and still think that the powder was smokeless or a mixture.
Amazing how many people don't know the difference.
Local guy borrows a muzzleloader, loads it with smokeless, blows it up, no injury, borrows another
loads it with smokeless, lets a friend have the first shot, friend gets a nipple in his forehead,
lives but right eye not very good. He had used pyrodex so bought a can of green dot because the can looked similar. " Black powder only" doesn't tell you much when almost all powder is black.

Definitely a case of extreme stupidity. But the stupidity in the cannon case was fielding it, knowing it had a structural defect.

CP

 

[Deadeye]

CP, I realize it's not pc but thought it might help as ,at the time, I wasn't sure where I'd be holding it when shooting. The touch hole is 1/8" so the guard does provide some protection. The breech was made of some chrome moly that I had laying around the shop.
The barrel was just a piece from a pile of them that I've cut from shotguns over the years. I just picked a piece with the thickest sidewalls.
The whole thing,including the tiller, with a steel
cover on the back end so it doesn't split when used as a walking stick, weighs exactly 2 lbs.