Benchrest cannon?

[Victor3]

 On big bullets for cannons, here's an example of some from a mould my friend machined years ago for a BP barrel made from a ~3' long 20mm barrel section with threaded breech plug. The bigger one, which we decided against firing, is 2.5" long and weighs 2700 grains. The shorter is 1.9" long, and has a parabolic-shaped base .600" deep. It weighs 1800 grains. The mould had an adjustable-depth base plug to cast different weights/lengths. The hole drilled in these here was to be for a hardened steel rod; we never got a chance to try it on plate though.





 To test fire, we strapped the barrel to an old FN machine gun tripod with hose clamps (I know, sounds like a bad yootube video). I can't remember what charge we used, but it was pretty stout. The bullets were lubed with Crisco.

 Unfortunately, we didn't have time to do much accuracy testing before it went to the guy it was built for. The bullets did go to within about a foot or so of where we were trying to hit at ~200 yards though. I was impressed, considering our 'high-tech' setup (I'll scan some pics when I get a chance).

 I'm thinking about making a similar style mould for my 12 ga muzzle-loader.

 Any thoughts on designs for accurate bullets, loads (lube, wads, powder, ignition, etc) for big bore rifled muzzle-loaders?

 What's nice for the small bore rifled cannon I'm thinking about building is the variety of off-the-shelf projectiles available. Developing an accurate load should be interesting...

[cannonmn]

Those projectiles have almost exactly the same lead bands as the original Krupp projectiles for rifled breechloaders.  The bands were lead, extended over most of the cylindrical part of the projectile body, etc.  See if you can find some pix on the web.  I have a few different sizes in the collections and if I get near them in next few days will get pix.

[seacoastartillery]

I wonder how it would work to make the entire carriage out of steel plate; trucks, cheeks, axles, everything.  Sure would dampen recoil.
  

     This idea is certainly aligned with the title and spirit of this thread.  Mike and I are working on a universal test mount which we hope is a quantum leap forward from the tired old landscape timber and steel block we have used for 4 years.  We are thinking heavy steel cheek plates and transoms securely bolted or welded and stress-releaved, then re-machined for parallelism and flatness.  We are also fighting the battle of the "benches".  Sounds like WWI without trenches, only benches.  Mr. Hi-tech is conjuring up all sorts of 1/4" thick aluminum torsion box construction bench tops and I want 5 layers of 3/4" Baltic Birch plywood glued and bolted.

     Victor,  please tell us a little about your ideas on how to use that 12 gauge "Paradox" tube.

Regards,

Tracy and Mike

[Cat Whisperer]

I have one cannon, 1/2" bore - 3" dia at breech that has a cascabel that screws into the breech.  It uses a 'washer' of copper to keep the pressure from reaching the threads.

The 155mm howitzer uses a neoprene type of obturation disk (protected with a stainless 'bowl' that seals the breech.  (Pressure on the bowl pushes on the neoprene type of material squeezing it sideways to seal it.)

[seacoastartillery]

     Although the De Bange Obturator has been with us as a bore sealing device for more than 100 years, at least we don't use asbestos fibers in a beef tallow matrix with a canvas and tin covering behind the steel mushroom!  I'd say Neoprene is real progress.

Tracy

[Victor3]

Those projectiles have almost exactly the same lead bands as the original Krupp projectiles for rifled breechloaders.  The bands were lead, extended over most of the cylindrical part of the projectile body, etc.  See if you can find some pix on the web.  I have a few different sizes in the collections and if I get near them in next few days will get pix.

 Cannonmn - I couldn't find a picture (and would like to see yours if possible) but I found a couple of good reads in the process...

http://en.wikipedia.org/wiki/Krupp

http://www.chuckhawks.com/bc_not_exist.htm

[Victor3]

I wonder how it would work to make the entire carriage out of steel plate; trucks, cheeks, axles, everything.  Sure would dampen recoil.
  

     This idea is certainly aligned with the title and spirit of this thread.  Mike and I are working on a universal test mount which we hope is a quantum leap forward from the tired old landscape timber and steel block we have used for 4 years.  We are thinking heavy steel cheek plates and transoms securely bolted or welded and stress-releaved, then re-machined for parallelism and flatness.  We are also fighting the battle of the "benches".  Sounds like WWI without trenches, only benches.  Mr. Hi-tech is conjuring up all sorts of 1/4" thick aluminum torsion box construction bench tops and I want 5 layers of 3/4" Baltic Birch plywood glued and bolted.

     Victor,  please tell us a little about your ideas on how to use that 12 gauge "Paradox" tube.

Regards,

Tracy and Mike

 M&T - I like the idea of all steel too. I think Dom makes some of his stuff that way 

 As far as bench tops go, can't go wrong with that "Ballistic Birch."

 Paradox... I had to google that along with "12 ga" to figger out what you meant. You're on target; I bought a barrel blank from Hastings several years ago for a big bore air rifle project that never got out of the CAD stage (design turned out to be unworkable). It's 1.25" diameter, 24" long.

 Won't tell much more than that for now - I want to pull the tarp off the gun in this thread after I have it in hand. I don't think anyone here has one quite like it...

[cannonmn]

Will try and get some more info on this one later, gotta run now.  Look closely and you can see marks on the band and some on base.  The small round potmetal thing is a closure plug for shipping, not a fuse.  Many Krupp projectiles were sold by Bannerman's and you can see them pictured in the old catalogs, maybe someone will post a photo from one of those pages that show them.  The band on this one is lead and the projectile body is cast iron.  Krupp made breechloading rifled mountain and field cannons in about any caliber you can imagine, since they sold them all over the world and they'd make any caliber the customer wanted, except for one the same or larger than the German equivalent gun, apparently.  I've heard this was a rule imposed by the German government in their decision to allow Krupp to sell weapons to just about anyone.  Exported weapons had to be made in a smaller caliber than those provided to Germany and its various states.

The projectile shown is probably for an 8cm Krupp steel breechloading rifled blackpowder cannon, ca. 1870-1890's.  The iron body measures 7.5 cm, the flat parts of the lead band are 7.84 cm diameter.   I have a 7.5 cm Krupp b/l blackpowder field gun that would have used projectiles like this (correct diameter of course) not far from where I'm sitting but don't have time to get pix at moment.

[Double D]

Double D, I think a carriage made entirely of metal is a good idea, the more weight the better. Here is one of my projects I am working on (slowly). This carriage is cast in aluminum as a test and I planned on casting the final carriage and trucks in zinc but now I think I will cast it all in hardened lead - depleted uranium would be better. Should weigh around 50 pounds or so and with a 20 to 24 inch barrel it would weigh around 70 pounds. Caliber will be around .75.

Max

I have meant to comment on the carriage every time I saw it. NEAT!

Here's the one in town sqaure in Pietermaritzberg



Max you did a good job building that carriage!

[GGaskill]

This carriage is cast in aluminum as a test and I planned on casting the final carriage and trucks in zinc but now I think I will cast it all in hardened lead...

I don't think lead (or linotype) is a good idea because, although dense, it is not very strong and you will need some strength to resist deformation due to recoil forces.

[Terry C.]

I think he was making a joke, George.

I have a large slab of aluminum, 1" thick x 8" wide x 12" long, that belonged to my father. I have no clue where he got it, he was a packrat (like me).

One of these days I'm going to build something with it. Maybe a billet aluminum carriage?

Someday...

[Victor3]

The projectile shown is probably for an 8cm Krupp steel breechloading rifled blackpowder cannon, ca. 1870-1890's.  The iron body measures 7.5 cm, the flat parts of the lead band are 7.84 cm diameter.   I have a 7.5 cm Krupp b/l blackpowder field gun that would have used projectiles like this (correct diameter of course) not far from where I'm sitting but don't have time to get pix at moment.

 Excllent cannonmn. I'd never seen one, nor did I know much about Krupp or his guns before now. Thanks much for the info 

[Cannoneer]

Hey Victor,

 I came across this video while I was searching Y/T for cannon firing vids for another thread. It's a larger bore than you're planning (golf ball) but it definitely shows a steel base/carriage design that you will not want to duplicate for your project. It seems like they grossly overloaded the tube in a few shots but even so I think it would be safe to say that this base design was prone to flipping.

http://www.youtube.com/watch?v=UwxuS_CQcVU

[dan610324]

                             IDIOTS


did you see the picture in the bloopers ??

its just an thin walled pipe

its idiots like those we read about in the newspapers
and Im sure we soon will do it again

[Victor3]

 An idea I've been kicking around for the benchrest cannon - I've got this blank, 12" OAL that I could get about 10" of bore depth using a rifled sleeve in. Chamber area OD is 1.69".



 I'd thought of turning down a BP rifle barrel for the sleeve, but came across these 50 cal, 11/16 OD, 1 in 20 twist rifled liners that might be easier to work with. The reamer I've got is .700, and I could extend it to get the required depth. I'd either solder or epoxy the sleeve in.

http://www.trackofthewolf.com/(S(uhggqd45ihl4o555bx2rf5et))/categories/tableList.aspx?catId=14&subId=142&styleId=510&partNum=LINER-50-ML-1

 What say you