Need advice: Building fireworks mortar/canon

[georgerkahn]

Fireworks were recently legalized in Iowa; I am more than satisfied with what I can buy at the local stands.
Being in my 70s it is a bit too little too late, but I still enjoy them, my wife says I have the mind of a 12-year-old.
The local authorities, being a bunch of *******s reduced the time we can shoot them off to July 3rd & 4th and only 5pm to 10pm.
I mean ***! the Fourth only comes around once a year! All the liberal little old ladies complain they can't sleep, more likely they like to make people miserable.
Anyway, I hope you are not one of these guys on U-Tube firing bottle rockets from their butt crack, not a pretty picture, but I still laughed like hell.
I wonder what the ER people thought?

You need to read about Pablo Ruiz -- who placed a mortar upon the top of his head, set it off, and did not live to tell others about it -- https://nypost.com/2022/07/07/texas-...loded-on-head/

[725]

IMO, trying to reengineer some commercial fireworks is asking for trouble. Trouble from the law (unknown to me if even there are such laws but it would be my luck), trouble from the ER Doc who just shake his head at your resulting dilemma, and that never ending trouble from the wife who will certainly say she told you so. YMMV. Good luck

[Oreo]

I understand the dangers here, but guys, what I'm doing is just making a black powder cannon. That it's a firework is, or should be irrelevant. Like any black powder firearm, it needs to not explode, primarily. After that, whether it launches a golf ball, or a firework, or a blast of sparks... it will be in a safe location pointed in a safe direction, etc. etc.

The question is how to get more range (muzzle velocity) out of a muzzle loader? I hear the add more powder. I wonder how much more powder would help before I'm just blowing it out the end of the very short barrel? But I don't know black powder very well. I'm used to smokeless powder reloading, and I only know that things are a bit different with black powder. That's where I need the education.

[Winger Ed.]

Over on the 'Graybeard's Outdoors' site, there is a section just for BP cannons and mortars.

It might be worth checking out.

[BLAHUT]

i know a guy and his kid launching 16 lb bowling balls using black powder> 1/2 lb powder per launch ??

[W.R.Buchanan]

So I buy these 60gram 5" mortars for the holidays. They come with fiberglass mortar tubes. The trouble is I'd like to fire these mortars higher. I'd like to get them twice as high, if possible, but even 25-50% higher would be good. I'm thinking this might be possible by using a longer tube and maybe a larger powder charge. Obviously, I'm limited by the delay fuse length, but I'm willing to bet there's still plenty of room for optimizing the launch.

I'm thinking of buying some super-heavy gauge steel tubing, say, 1" thick walls, and double or tripple the length of the original fiberglass tube. Same bore diameter, which is pretty loose. I figure on tack-welding a steel plate as the bottom of the tube. I'd rather the welds break than the tube explode.

But, I might be way off base on all this. Please guide me to success.

I'd say you are just a little too far on the safe side for this application. Most of the Fireworks Mortars I've seen were made from Sonotube (Rolled Paper Cement Forms)

I have a friend who made a Bowling Ball Mortar from 8" ID Cro Moly tubing with a 1" wall thickness. When they proofed it with 1 lb of Black Powder is shot a 16 lb bowling ball 1 1/8 miles! This gun is so strong it could swallow a pound of Bullseye no sweat. It typically shoots a bowling ball 1000 feet strait up with only 3 oz of black. See pictures below. This thing takes four grown men to move!

You could definitely go with some 5-6" heavy mailing tubes or Sonotube for your barrel. For Sonotube go to you local Home Improvement Center and look around.

Randy

[Rapier]

If it were a solid ball it would be just increasing altitude, but the payload charge has a delay fuse which will still detonate at X seconds regardless of altitude. It is all timed, launch propellent fires, lights the charge’s fuse, etc. You do not want that charge to go off at head level, it contains neat things like magnesium and phosphorous, to make those pretty little sparkles that burn for a long time, could seem like a lifetime.
Suggest you leave it like it comes in the package.

[17nut]

Main problem is that the main shell is paper mache and has a finite structual threshold.
Accelerate it to hard and it will collapse in the tube

Many years ago i made a mortar for shooting beer cans.
18-20grams~275-310grains of BP under a concrete filled beer can.
It went out of sight at the peak and out of 10 shots i recovered 2, the rest did a mole and disappered down (more than 2 feet).
Point is: At some point i tried to launch filled cans with a light load and all i got was wet as the cans collapsed at the end of the barrel.

[Oreo]

The structural integrity of the projectile is definitely something I have to give consideration to. I can probably make some inert for testing by removing the guts, and replacing with equal weight of sand, or something. I can test till I understand the limits of the canister.

[17nut]

Sand and BP arent the same, try damp soil, might be closer.
It's not the actual weight but rather the shift in displacement that's the main problem.