Mystery Tube

[Cannoneer]

I've been sorting through my photo files, and ran across these pics from a long past eBay auction. I didn't record any info, because I never intended to keep the pics, so I'm just going by memory here. The seller said he made this thing out of steel, it was made to be fired, and the reason he was letting it go, was because he didn't have the time to finish it. The auction never ended, the item was removed.

I'm just curious to hear some other opinions on this thing. My opinion then and now is that it was never intended to be a cannon, that it's something else, I just don't know what. The only way that this tube could have been machined to be a cannon barrel, is if the maker was a perfect idiot. Taking into consideration the thin walls, and the design of the threaded breech plug; how could anyone have ever intended to fire this thing?

[Victor3]

 Only problems I can see from a design standpoint are the groove on the bbl at the breech and (maybe) a too thin wall near the muzzle. The bore in the plug was probably designed as a powder chamber; wall thickness seems enough.

[Cannoneer]

Only problems I can see from a design standpoint are the groove on the bbl at the breech and (maybe) a too thin wall near the muzzle. The bore in the plug was probably designed as a powder chamber; wall thickness seems enough.

Victor,
Like you, a reduced powder chamber in the breech plug is one of the first things that came to mind, but here are a few things I find problematic about it. The vent: It would have to be drilled through the threads on the plug, and its placement on the tube would be in the area where that decorative groove was cut. How would he align the vent, would the plug be tightened hard or just snugged up to align the two channels? Would heavy use of the cannon, and wear on the threads eventually lead to a misalignment of the two vent channels? 

Dependent on what flavor of steel it's made of (4140, 416R, etc.), I would agree with you that the wall thickness at the breech is fine; so why didn't the maker just leave the plug solid, and bore the vent down through the smooth surfaced single thickness of the tube.

That groove/channel on the tube by the breech that you mentioned: Why in the world would someone take away all that metal in such a critical area? 

You and I have both seen cases of fine machinists making some unorthodox artillery pieces, simply because of ignorance of the subject matter, but so many things on this barrel just don't make sense to me.

[Ex 49'er]

The vent could be in the nipple on the back of the breech plug.

[Cannoneer]

So, how about making it an "in-line" breech loader like the Whitworth 12-pdr? Well, in this case I think it would be a much better plan than going with a conventional vent.
I wonder if there's enough metal in the front end to have it rifled? Ha!

[GGaskill]

The hand held firing picture makes me think this might be used as a swivel gun.  It certainly couldn't be hand held with any kind of shot load.  Or maybe a bazooka.   

Although I, too, first thought axial vent, perhaps the vent is in the cascable.  That is where it should be with the chamber in the breech plug.

[Cannoneer]

Okay, so we're going right down the middle, in-line it is, and in-line it's got to be. The other three givens are that it's a smoothbore breech loader with a reduced powder chamber (not an easy feat), and we know that in a certain era, smoothbore plus reduced chamber adds up to howitzer.