Smoking Mortar Rounds?

[Evil Dog]

A mortar round that leaves a smoke trail in flight... now that could be interesting.  Seems to me that one of the hollow ball rounds could be filled with some combustible material that should leave a visible flight trail.  It would mostly be a question of how to go about it.  Would also want it to be refillable/reusable.  If not leaving a flight trail then perhaps some sort of fused device that would let out a smoke cloud where it lands.  One of the BIG questions though is would such a round run afoul of the ATF as being an "explosive device" or some such.  Your thoughts?

[rampa room artillery]

well I guess it would be as legal as a flare?? right? not explosive just burning.
you could mix baby powder or flower with potasium nitrate? kinda like slow match but in a plaster form.


rick bryan

[cannonmn]

You should call your local BATF office to get the correct information. 

The amount permitted in any kind of projectile is tiny, like 1/4 ounce of any combustible or explosive chemical.  This isn't the same case as a road flare since a road flare isn't a cannon projectile.  The only exemption I know exists is if you are on a US government-owned firing range and the rules for the event permit the firing of live shells.

[Blaster]

Hmmmm.  It wouldn't be for a mortar and I'm certainly NOT suggesting it nor would I even condone it but I wonder if anyone has launched an ignited road flare (fusee) from say perhaps a one inch bore cannon, if it'd even fit the bore.  Would really be not only dangerous but a BIG fire hazard too.  I'd think that this procedure would be more than a little frowned on by the BATFE folks.

[Artilleryman]

I know that many of the posters here use small mortars that might make it difficult to follow the flight of the projectile, but if you are using a full scale 12 pdr or larger full scale mortar you can watch the flight of the projectile to reasonable ranges so having a smoke trail doesn't seem necessary.  On the other hand having a smoke trail would be interesting, just be ready to put out fires.

[Victor3]

 Mr. Dog,

 IIRC, you're in CA, right? Me too, and I've looked into some way to do it here legally. I don't believe it can be 

http://ag.ca.gov/firearms/forms/pdf/Cfl2007.pdf

 Scroll down to page 22. My reading of the text indicates that shotgun tracer ammo and flares are the only CA legal projectiles containing any kind of burning stuff.

 You could probably get away with attaching a long streamer to the ball if there's no possibility of scaring a California Condor with it 

[Double D]

Ed,

I attached a streamer to one round using a screw eye.  But frankly I wasn't able to pick the ball up in the air any sooner than without.  For me what increased the visability of the ball was size of ball,  velocity and direction of the sun.  Smaller balls are of coarse harder to see.  If you reduce your charge and slow the ball down it's easier to see.  If you keep the sun at your back or a least in the rear quadrants you will be better able to pick up the ball.

[Evil Dog]

I often will attach a nylon web streamer to the ball.... as long as I keep the powder charge down it will usually survive the flight.  Some times I will be able to see it in the sky but more often than not... not.  However, it does make finding the ball on the ground much easier when I go looking for it.  Being cast from zinc the balls can usually be fired a half dozen or more times before needing to be recast.

[RocklockI]

To even get 106.0 Gr's 1/4 of powder IIRC into a 2.250" shell (pool ball) drilled straight is pushing the drill size , to me anyway w/wood plug type fuse .

I think 1/4 OZ. is plenty for ANY size mortar tracewise . It sounds like alot of fun to trace and time small "pops" in the air . Up here and in Colo. ......you'd better be prepared for any kind fire possible fire that may ensue.....!  I would never intentionally try and place a "smoker" for easy finding anywhere around here . Talk about out running your headlights ......

rocklock

[Eyes Of Death]

You could use the 60-40 potassiumnitrate and sugar mix. Just drill hole melt the sugar and potassium pore in let harden and shoot.

[Double D]

Yes I did lock this post until I could look up what the stuff is that is mentioned in the previous post.  Before I could do the research and unlock the topic Wife said Honey Do and I did...forgeting to come back an unlock.

[Evil Dog]

I've pretty much decided to abandon the pursuit of a smoking mortar round... just too much chance of running afoul of ATF, Calif DOJ or other agencies that I haven't thought of.  A nylon web streamer attached to the ball is legal (as far as I know) and serves the purpose.

[Artilleryman]

Streamers will shorten the range for a given powder charge considerably.

[cannonmn]

OK, here ya go, how 'bout a Rube Goldberg smokin' mortar round that's completely legal:

Type 1:  Glue a patch of canvas on the back side of the shell and dampen it with less than 1/4 oz of WD-40 just before loading it.   The WD and canvas will burn off leaving a smoke trail, we've done it with cannon projectiles but not mortars, so maybe, maybe not.  Use care if fire hazard present, don't do it in states where it is not legal.

Type 2:  Make cavity in projectile that will hold a CO2 cartridge that will puncture itself by inertia on a tack-like thing when  the round is fired.  Of course the rupture disk on the cartridge points toward breech of mortar, and tack-like thing is in contact with it.  Put something in to restrain the cartridge from exiting the shell, maybe hold with setscrew.  Put in some inert smoke-making powder like flour or whatever that will be blown out gradually by the CO2.  Maybe there should be two holes, one to insert CO2 cartridge, and another maybe 1/4 inch or so dia. to allow flour dust to exit.  If anyone gets that one to work, please make a video to show us.

[MikeR C]

I too have considered smoking rounds to be fired from a cannon/mortar. Skylighter sells bulk smoke mix and a paper/clay projectile could be fabricated to contain it and survive being shot. I have also read the ATF rules about the amount of "incendiary/explosive" allowed.
If I wasn't so lazy I would send ATF a letter stating my INTENT was to produce a "signalling" device.
Take the Winchester cannon and their ilk that use shotshells, if the INTENT is to fire a projectile then the cannon is illegal but if the INTENT is to make noise it is legal, they will chamber both.
If the INTENT of my smoke shell is signalling not starting a fire is it still an incendiary device? Especially if it is a commercially available "smoke" powder?
The fire hazard aspect of firing such a shell should be moot.
Maybe someone out there is not as lazy as me?

Thx
MikeR C

[Double D]

Mike this topic comes up often.  Kind of gets into a gray area of the law, I think. Is a smoke round an incindarary or pyrotecnic? It might be nice to have a letter from ATF. 

Such a letter would have to have a description of how the system works and how it would be employed. I don't know how they would respond to something intend to emit smoke so the round could be recovered for reuse. Why don't you write the letter and post it here.  It would be nice to know. 

[ShadowMover]

Let me say first off, I have not tried this. There was a book on amateur rocket making that had a trick using kerosene or light oil as a smoke maker. It did not involve any combustion. The idea was to have two holes in a cylinder tank above the rocket engine. The cylinder was full of kerosene. The upper hole in the cylinder was open to the air, and the lower hole had a small cork or piece of tape over it. When the rocket reached any sort of speed, the tape or cork was blown off by aerodynamic pressure and the kerosene or any NON- volatile liquid, such as anti-freeze, light oil, or even colored water, would be sucked out the lower hole and turned to a mist resembling smoke.

A similar trick is used by the Blue Angles and other aerobatic teams to make red, white, or blue smoke. If you introduce a non volatile liquid into a fast moving air stream you will get a smoke like mist. It might take a lot of colorant or dye to make the liquid appear colored, white is the easiest.

I'll leave it up to you guys to figure out how to make a chamber with two holes in your mortar shells. Remember, the liquid won't come out unless air is pushed in, or a spring is used to push it out. The speed of the shell should do the rest of the job. The should be no problem with any regulations using a method like this.