No tank barrels allowed

[Cannoneer]

Artilleryman, guardsgunner, rampa room artillery and also anyone who isn't a member of the N-SSA, I had read the Competition Regulation: Rules for Artillery on the N-SSA website before, and I always meant to pose this question to Norm; what is meant by 'no tank barrels allowed'? I wasn't sure if this statement was to be taken literally, or if "tank barrel" was a reference that described something other than its obvious meaning. Well, now I think I know; when I was searching for some photos of US CW limber chests I came across this website that has some items offered up for sale.

Whats funny here is the description of the gun for sale: "AUTHENTIC 10 LB. PARROT", and later in the sales pitch, "CANNON BARREL IS MADE FROM 90MM RIFLED TANK BARREL."

http://www.octagonlr.com/civil_war_artillery.htm

[moose53]

Is anyone else the least bit nervous about the weld ringing the barrel right over the powder chamber on the 90mm tank barrel.

[guardsgunner]

Boom J,
   until more recent time; tank barrels were being used as barrel liners in the N-ssa.The rules were changed sometime in the 90's to get to a more civil war system. (Parrott rifleing is near 1 turn in 10 feet). It was about the same time the ruled out scale guns. Both are still being shot in the N-ssa having been "grandfarthered "in. Artilleryman knows the particulars better than I.
 

[cannonmn]

Is anyone else the least bit nervous about the weld ringing the barrel right over the powder chamber on the 90mm tank barrel

Really hard to tell, I can't see any weld, maybe you are assuming there must be one at the front end of the reinforced section?

This is kind a krazy looking rig, but it might shoot well.  As for safety, you would have to ask the maker how it was put together, where the welds were, what kind of welding was done etc.  I've tried to weld modern military cannon barrels using ordinary electrodes and it did not work well, I got no penetration.  You need some trial and error and the proper composition of electrode, not to mention enough amps to get the penetration required for a strong weld.

I like the modern military cannon barrels because they were designed for much higher interior ballistic pressures than you will get using black powder.  Don't get overconfident though since the weak point will usually be any welding you do that isn't optimized for the particular alloy that the military gun barrel happened to use.  I have some 30mm barrels from the A-10 Warthog aircraft, and they are made of such hard steel it is all I can do to cut them, much less weld them.  I have to use an abrasive chop saw, the guillotine bandsaw won't even scratch these barrels even when I use the more expensive bi-metal blades.  These barrels were already de-milled (chambers cut off and destroyed) before I got them, it wouldn't make economic sense to destroy an intact, chambered barrel.

[Double D]

Is anyone else the least bit nervous about the weld ringing the barrel right over the powder chamber on the 90mm tank barrel.

Not if the Tank barrel is prepared as per N-SSA guidleines as a liner.   I breech plug is sweated in and welded in place.  The weld being well away from the chamber.  The barrel is then inserted in the bored out barrel.

Some one with proper knowledge of cannon construction and advanced welding skills shouldn't have any problem problems welding these barrels.

The problem comes when some one builds a cannon on one of these barrels with out the proper skills or knowledge.    We see dangerous examples of this on youtube and in the news all to often. 

Blackpowder is a nasty Genie...and when the Black powder genie breaks out the bottle it isn't always pretty.

[Cannoneer]

Boom J,
   until more recent time; tank barrels were being used as barrel liners in the N-ssa.The rules were changed sometime in the 90's to get to a more civil war system. (Parrott rifleing is near 1 turn in 10 feet). It was about the same time the ruled out scale guns. Both are still being shot in the N-ssa having been "grandfarthered "in. Artilleryman knows the particulars better than I.

Guardsgunner, when I first read this rule, I made the guess that it meant a rifled tank barrel used as a liner, because I figured that the officials writing the rules would have always stipulated that the cannons would have to possess the accurate profile of an original CW gun. I also made the assumption that these rifled barrels might have been banned because of their superior accuracy as opposed to members firing either original rifled barrels or realistic reproductions.
I'm probably mistaken in both of these speculations; it'll be interesting to hear what Norm has to say on this subject.

[Cannoneer]

Is anyone else the least bit nervous about the weld ringing the barrel right over the powder chamber on the 90mm tank barrel.

Really hard to tell, I can't see any weld, maybe you are assuming there must be one at the front end of the reinforced section?

Moose, I'm also not sure which photo is showing a weld "right over the powder chamber" of this cannon. The only pic that I figure might fit your description is this one, showing a side view of the breech reinforce band. If that is a weld in front of the band, then it looks to be a pretty substantial weld.

[dominick]

Is anyone else the least bit nervous about the weld ringing the barrel right over the powder chamber on the 90mm tank barrel.

YES!

[GGaskill]

Perhaps a sharp blow from a sledge hammer would proove it.  If the weld breaks, it was dangerous.

[Cat Whisperer]

Is anyone else the least bit nervous about the weld ringing the barrel right over the powder chamber on the 90mm tank barrel.

Just to play it safe, I do NO welding anywhere near the powder chamber.  If I ever have a need to do so it will be done by a CERTIFIED welder after much discussion of design, materials and processes.  (I have a friend who is a professor at the local CC and certifies welders.)

[Artilleryman]

Boom J,
   until more recent time; tank barrels were being used as barrel liners in the N-ssa.The rules were changed sometime in the 90's to get to a more civil war system. (Parrott rifleing is near 1 turn in 10 feet). It was about the same time the ruled out scale guns. Both are still being shot in the N-ssa having been "grandfarthered "in. Artilleryman knows the particulars better than I.
 

I can't add anything to this.  As I understand it, this was a move to be more authentic.

[moose53]

The problem is not so much with the weld as where it is. Modern barrels are heat treated and to bring the barrel back to spec you would have to reheat treat to whole barrel after welding. Because the weld is so big he had to have put a lot of heat into the weld area. I have made rollers before for our sawmill that where welded beautifully but because the weld was over a stress point they lasted less then a week. I moved the weld maybe 1in and it worked just fine. That 90mm tube scares me.

[Cat Whisperer]

The problem is not so much with the weld as where it is. Modern barrels are heat treated and to bring the barrel back to spec you would have to reheat treat to whole barrel after welding. Because the weld is so big he had to have put a lot of heat into the weld area. I have made rollers before for our sawmill that where welded beautifully but because the weld was over a stress point they lasted less then a week. I moved the weld maybe 1in and it worked just fine. That 90mm tube scares me.

The rollers (like cannons) see that small - but repeated - stress.  Well within the strength capabilities of the material until it work-hardens a little and becomes brittle.

[cannonmn]

Modern barrels are heat treated and to bring the barrel back to spec you would have to reheat treat to whole barrel after welding.

I'm no metalurgist, and I'm not even that experienced as a welder, but all this goes to show that you should try and find out as much as you can about the steel you are working with.  It could be that a modern cannon barrel is good for 120ksi when fully heat-treated and new, but if fully annealed (what I mean is that any strength added due to proper heat treatment is removed) is only good to 80ksi.  In that hypothetical case, I think I'd still feel safe using it for black powder shooting.

I actually had to think about this because I was offered some 120mm barrel sections from an M1A Abrams tank.  The smooth bore diameter (4.7 in.) was pretty close to a 12-pounder smoothbore spec., so I was tempted.  The design spec on the barrel when new was pushing 200,000 psi, or so I was told (maybe it was only 180 and I forgot, but it was really high.)  The steel in it was pretty special but there wasn't a lot of demand for it, that's why I could have gotten them cheap.

[Cannoneer]

Boom J,
   until more recent time; tank barrels were being used as barrel liners in the N-ssa.The rules were changed sometime in the 90's to get to a more civil war system. (Parrott rifleing is near 1 turn in 10 feet). It was about the same time the ruled out scale guns. Both are still being shot in the N-ssa having been "grandfarthered "in. Artilleryman knows the particulars better than I.

I can't add anything to this.  As I understand it, this was a move to be more authentic.

Then the changes in current rules that will not allow tank barrels to be used as liners, and also do not permit any less than full scale artillery reproductions, were put into effect to achieve a greater degree of realism; but would this loose rendition of a Parrott rifle (even if it were judged by consensus to be constucted in the safest possible manner) ever have been allowed to be used at an N-SSA event, or was it always a rule that even smaller scale models of real CW artillery pieces had to be exact in their representation of original cannons?

[Artilleryman]

AS far as I know it has always been required to have an accurate scale model, and now a full scale model.

[rampa room artillery]

  From what the artillery officer has told me the board was afraid that some one would figure out how to shoot these old military surplus barrels better then a correct barrel, tho no one has yet and probly wont, the twist is to fast for our slow burning powder and soft lead pellets the lead just strips off. and is left in the bore. there is only one gun left in th nssa tha is grandfathered and kept up its inspection and it has not been shot in a few years. as far as i know.   and they can only be bored out to have a new liner if you want to go throw a few bits and if i remember right a 3.5 in bit for a lathe is 1500 or more, so no thanks.

   

  I am going to the fort good friday weekend to shoot my new mountian rifle nad sight it in for nationals.
  see you guys up there dont for get NSSA guns.  they have changed the scoring rings. you  have to hit the counter battery not just the ring. so no more 50 5V  at nationals. yay.


 rick bryan
 3rd va co B
 nssa