Dominick Carpeter's BP mortars

[Who_Dares_Wins]

Dominick Carpenter's site has changed but he is still making golf ball, billiard ball, and soda can mortars. I haven't talked to him about cannons.

https://blackpowder-cannons.com/

Write him at cannonfab@hotmail.com

I bought a soda can mortar from him about a month ago and am having a great time with it.

Last weekend I shot my mortar in a fallow hay field using beer cans I cut to 2.65 inches and filled with Rockite. I won't do that again. Rockite expands.

The cans weighed 6,875 grains (+or- 20 gr). With 175 gr of FFFg they went 350 yards when elevation was set at 45 degrees.

I had an 18 inch length of white cloth attached to a hook I set in the Rockite. It would have been hell trying to find the can in the rolling terrain without it.

I couldn't see the can in flight until the cloth streamer was visible just before it landed in front of the dark trees that were about 50 yards beyond.

Next time I'll be using tennis balls filled with sand with discarding gas checks made from beer cans. The sand is free and so are the cans I find along the road. It's much easier to control the weight using sand. They weigh 2,830 grains. The gas checks weigh 75 grains. I'll start with a load of 100 grains FFFg.

I do it for the exercise as well as having fun with the mortar. Kind of like chasing a ball around a golf course. 350 yards is about as far as I want to walk back and forth between shots over uneven ground. I have bad knees. Five shots would be about two miles.

I started out firing the mortar with cannon fuse but disliked having to run away  and then turn around to watch. So I bought an inexpensive wireless 4 cue (4 channels for 4 mortars) fireworks ignition system.  I thought I could be well away when I hit the 'fire' button and have a chance at watching the can in flight. Nope. Didn't work. Only saw it a split second before it landed in front of the trees.

When I first got the system I used orange wire eMatches (store bought) in the fuse hole. But I get more DIY satisfaction making nichrome wires that have been coated with a homemade nitrocellulose lacquer mixed with magnesium powder to give it more of a spark.

I think it's safer to use an instantaneous ignition. The situation downrange could change while a regular fuse is burning.

Someday I'll try to chronograph it with a horizontal shot. Just guessing, but I think it's going less than 300 fps. Maybe the tennis balls will be a bit faster.

The design of the mortar is interesting. The barrel of the mortar is 7 inches deep and has a bore of 2⅝ inches. The powder chamber is a 3/4" ID tube that sticks up about 1⅝" from the bottom of the mortar. With the projectile sitting on top of the chamber there is a good burn, gas development, pressure build up, and then the volume of the barrel opens up and the pressure goes way down. (That's basically how shoulder fired grenade launchers have been made since the Vietnam war.) Dominick said he uses much less powder to get better results compared to when he made them without the powder chamber. I use a drop tube to get the black powder in the chamber. It came with the mortar. I haven't packed it down like I do with my 54 cal Lyman Great Plains Rifle. I'll have to get a dowel and try that.

[Graybeard]

I have a fire cracker cannon from Dom. I'm not really into big cannons but do like small ones that fit on book case shelves. It's the only one I have that is actually fire able, the others are strictly ornamental.

Good to hear Dom is still in business and doing well. I hope to see more cannon activity over here. Honestly the cannon forum is about all that is keeping the go2gbo site running these days.

[Double D]

Dom is still our go to guy for stuff.  I am getting ready to send him some wood-the cheeks to my carriage so he can make cap squares for me. 

I use electric ignition sometime also. But fuse is so much more fun. Allow about an inch of fuse outside the  barrel.  Light the fuse and step back a couple of steps and wait.  If you have to run away from your gun and can't stand next to your cannon when you fire it, it is not safe.   

If you can't see the can fly when you fire you have too heavy of a charge.   Reduce your charge until you can see the can in flight. You don't need a streamer. Screws up the flight anyway.  90 grains is a massive charge in my popcan cannons.   100 yard range  is perfect. You can see the can in flight all the way down range, with practice.   Stand an old wooden pallet up at 100 yards and aim  at it.  Pretty exciting when you hit it.  Resounding  crack and splinters fly everywhere.

Don't get me wrong, I shoot my mortars long range also.  We recovered one of my bowling balls 1.4 miles down range. (Measured with GPS.)  But there are 3 more bowling balls still down range closer to 2 miles.  But if you can't find them  or see where they hit, it didn't happen.  Short range is much more fun.

Rotometals https://www.rotometals.com/2-59-zinc-cannon-ball-pop-can-mortar/  has popcan size zinc round balls.  Metal prices are up right now so they are a tad expensive, but you need a couple just to have them. The zinc round balls are reusable.  Fire them, go pick them up and fire them again and again...You can't always do that with the cans.  Shorter ranges also with these as you don't want to loose them.

Be sure to wash and dry them after each shooting session just like your mortar.  Zinc corrodes. Paint them black, they'll look cool.  Black is easier to find than fluorescent orange.