Recent shoot

[Will Bison]

Here's a few pics from a big shoot last weekend.  This was at the Mustang Range, East of Reno, NV. It was billed as a machine gun shoot but folks had all kinds of other stuff.




The moment of ignition. I suspect the ball has just started to move down the bore. I told the Lady with the camera to click it when she saw the smoke at the touch hole. She obviously had a fast finger.



I used a fuse to ignite it here, something I rarely do, but this was a well controlled range and I felt it was safe to use a fuse. This was a round of canister aimed at an old bus body. Sorry about the smoke. Look to the left of the left wheel. You can see the dust being lifted off the ground from the muzzle blast.



This is the 27th gun I have built/restored. I had a nice section of rifled 47 m/m gun tube and built this gun to fit in a standard pickup truck. It's just shy of eight feet long, 47 inches wide (fits inside the wheel wells) and three feet high. Tips the scale at 400 lbs.

I take full credit for NOT doing the wheels and NOT doing the machine work. I know when it's time to farm out work. The rest I did myself. I used all red/white oak laminated. At one point I considered poplar or even douglas fir but the computed weight was not what I wanted. Fir would have given a weight of less than 300 lbs, too light. The oak was a bit $$$$$$$$$$$$$.

Ammunition is either a 20 ounce round lead ball or a 21 ounce canister round of 28 sixty caliber balls. Canister is made up in an aluminum foil cartridge just like the powder charge. The ball is patched and the canister sits on a 5/8 thick sabot of OSB plywood. A charge of between 2 and 5 ounces of BP develops 750-1200 fps at the muzzle. For blanks I found 8-10 ounces of 3fg works great. (I figure a 35 m/m film canister = 1 oz, it's actually just over an ounce.)

So far I have put about 350 rounds of live ammo down range. Most of the time the gun is used for salutes with blanks.

! A NOTE OF CAUTION !  If you have read all the safety info on this site you will no doubt note that I violate some of the rules. My procedures and loads are for my gun only.

[Double D]

Even though you have added your own caution, as Moderators we are obligated to point out that the use of patched lead projectiles in large bore cannons is unsafe.

Cannons because of their size have a completely different set of working pressures than small arms.  Windage is required for safe firing.

I think with a little experimentation you will find that your cannon can be very accurate without being patched. You will also greatly reduce the chance of catastrophic failure.
 
For more information on the extremely high pressure at work in cannons  I strongly urge you to pick up a copy of M.C. Switlik's book the More Complete Cannoneer. If you check our resource list posted at the top of the forum you will sources for Switlik's book.

Now the safety notice is out of the way...Neat gun.  Tell us more about how it is constructed.  How accurate is it?

Especially tell us some more about constructing cannister rounds.

[Will Bison]

Thanks for your comments Double D.

I should clarify that my "patch" is a .015 piece of pillow ticking. The ball is 1.800, the bore is 1.850 and the groove diameter is 1.875. The patch only serves to keep the ball from rolling out. I can load it with pressure from one finger. I still have quite a bit of windage.

The barrel is a section from a gun originally chambered for the 47X285R cartridge. This was an anti-tank round from WWII used by the Japaneese in their Type 01 (1941) gun.

I do have Switliks book and many others and strongly reccomend it to cannon shooters.

The barrel was proof tested with some "extreme" loads before putting it on the carriage. The breech was made from a heat treated solid billet of 4000 series steel 6.00 inches in diameter. This was bored and threaded onto the barrel.

I did find that the rifled bore serves no purpose other than cosmetic appearance. There is no way to get a tight patched ball down the bore save hammer it in, a procedure I have no intention of attempting. The twist is about one turn in 9 feet by the way.

With a 2 ounce charge of G-O "cannon" it shoots about as accurate as a smooth bore. I have found that there is no reason to exceed 2 ounces although it will handle the 5 ounce load quite well. The initial proof loads were waaaay more.

The canister rounds are a simple aluminum foil tube closed at one end just like a powder packet. The 28 balls are dropped in and the end twisted shut. A sabot of 5/8ths plywood is seated on top of the powder and followed by the canister packet. This sits on top of a 2 ounce charge. Beyond 75 yards the spread is too great. At 75 yards a 50 gallon drum is a challenging target. I suspect the rifled bore is a disadvantage when firing canister.

[Double D]

Where did you find a Japenese anti tank gun barrel?  Did you consider making a Whitworth or other early breech loader.

The way you are using the patch does make sense and you still have windage.  

You want to visit the link how to hunt a deer with a cannon and see how that fellow constructed a cannister round.  Although some people find that post offensive because he succesfully hunted a deer with his cannon, there are some very good construction tips in there.

[Will Bison]

The Jap gun barrel was provided by Gen Douglas McArthur. Seems he needed ballast for the Liberty ships returning from Japan after the war and they loaded up all the war material in Tokyo Harbor. It wound up in Tooele Army Depot in Utah. Some years later the Navy needed targets at several gunnery ranges in Nevada. After many years of being shot at and bombed the Navy cleaned the ranges and all this "stuff" wound up in a scrap yard. From the story I heard there were several hundred tanks and guns all blown to bits.

I learned about all this too late or I would have been at the scrap yard myself. As it worked out, an aquaintance of mine had picked up this chunk of barrel in a trade. He picked it up for possible use on a race car () and it was laying in his shop when I happened by for a visit. He had no idea what it was and had wondered about the funny "splines" in the bore. When I told him what it was and that I wanted it a deal was struck for $20 USD. This all happened about 20 years ago.

The barrel layed in my shop for another five years as I had several other cannon projects going at the time. Eventually I got around to construction and finished the small gun over one winter. So that's the story.

I checked out the Deer Hunt site several weeks ago and got quite a laugh out of it. For my small bore the foil cylinder works as well as or better than a can. I use an adjustable hole saw to cut the sabots and found that the sabot is the trick. I had originally tried a thick felt wad but was disappointed. The sabot seems to hold a tighter pattern. The rifled bore does impart some spin and opens up the pattern when I compare it with a friends smooth bore of similar caliber. The canister is fun when we occasionally construct some "outhouses" of scrap building material.

Our recent snow has curtailed any thought of shooting for the remainder of this year, the range is a mud hole now and won't dry out 'till Spring.