Dischargers, smoke generator, 4 inch

[Chris Suslowicz]

Originally Posted by rob love

I happened across this manual while putting away duplicate books for in the library here in the RCA Museum. It answered a few questions about the 4 inch dischargers, such as how far the smoke cannister was projected (A: aprox 125 yards). I don't have access to the room with the scanner right now, and as well the book is pretty new so I don't want to fold the pages over, so you'll have to be happy with photographs.

The manual also covers various 2 inch dischargers as noted on the index page, however I have not copied those pages. If someone really wants to see them, let me know and when I get time I can photograph those as well.

The bad news for anyone in the UK is that that particular smoke discharger will come under Section 5 of the act, because it's short enough to be classed as a pistol. (So if you want one, or want a gunsmith to make you one out of No.1 Rifle parts, it will have to be deactivated and welded into a single lump.)

This is probably just as well, since if it can launch a can of soup 125 yards it's not something you want to stand in front of.

The canisters themselves are probably s5 as well, since the wartime ones were most likely white phosphorus filled (even the later HC ones would be fairly nasty in a confined space - powdered zinc and hexachloroethane, I think (has to be manufactured in very dry conditions as it can be initiated by water)).

Chris.

[horsa]

In the USA it is classed as a short barrel rifle (SBR per ATF) so also a device that has to be registered but still very legal to own. The smoke generator could probably be fabricated from an automobile oil filter, just a matter of finding one of comparable dimensions. Could probably hog out the internal paper filter and replace with smoke composition and some cannon fuze into the center with a black powder booster that would light from the blast of a grenade launching blank.

[horsa]

Attached image was downloaded from another thread a long time ago but figure it should be part of this discussion to consolidate information.

[Lynn Eades]

"hexachloroethane" Chris, is this the stuff in my tooth paste?
Do I need a different brand?

[David Dunlop]

A few years ago I wrote the Enfield Arsenal in England asking about these dischargers and canisters and eventually got quite a package of material back from them including machinists drawings for both the Ross Rifle and Enfield based versions. I believe the package also included detail drawings for the canisters. Should still be in a filing cabinet downstairs somewhere. The centre base of the canisters had a very simple detonator fitted which was basically two thin metal discs with a sandwich of something like mercury fulminate in the middle. The pressure blast of the firing cartridge was sufficient to set the detonator off, thereby igniting the propellant charge. Probably not an item you would want to drop.

David

[Chris Suslowicz]

Originally Posted by Lynn Eades

"hexachloroethane" Chris, is this the stuff in my tooth paste?
Do I need a different brand?

Yes, and no.

It's commonly used as a disinfectant/antibacterial ingredient and is perfectly OK in that application (very low concentration).

It's very nasty in screening smoke (HC) because the reaction products are lots of zinc chloride (corrosive), with some hydrochloric acid (ditto), and also carbon monoxide and phosgene (carbonyl chloride (COCl2)) mixed in.

Still much better than phosphorus smokes, though.

Chris.

[Jim Burrill]

As David Gordon says, we can have a live, fireable discharger here.

I have plans afoot to make an actual smoke canister that meets local reenactment safety guidelines.

Essentially, smoke compound as used for paintball games filling a cardboard cylinder, all made with no metal parts and weighing no more than one pound.

A blank .303 to ignite it and throw it down range a bit. Not an accurate tactical recreation in distance and duration, but usable for reenacting displays.

Intend to mount them on the Humber Mk4 Armoured car.

[Ron Pier]

Thanks Marco. I'll give the dimensions to my brother in law to save him saving all those wrong size oil filters. Ron

[wheaty]

Launching rounds are NOT blanks?????
The proper cartridge had a charge of BALLISTITE
A blank charge is a much faster powder and will result in major damage if attempting to launch a canister.
Blanks are manufactured for sound and effect with no barrel restrictions unless used in a semi auto. Restrictors were used for some arms however as a shredder in the case of a wooden bullet blank.

[Lynn Eades]

To add to that, The ballistite 303 has a flat end. (finished with a purple sealer)
The blank is crimped (like a shot gun cartridge) to a blunt point. At least that is what I have seen.

[Chris Suslowicz]

Originally Posted by Jim Burrill

As David Gordon says, we can have a live, fireable discharger here.

I have plans afoot to make an actual smoke canister that meets local reenactment safety guidelines.

Essentially, smoke compound as used for paintball games filling a cardboard cylinder, all made with no metal parts and weighing no more than one pound.

A blank .303 to ignite it and throw it down range a bit. Not an accurate tactical recreation in distance and duration, but usable for reenacting displays.

Intend to mount them on the Humber Mk4 Armoured car.

Hmmm....

Have a word with your local pyrotechnics/firework manufacturer, since the obvious choice is a 4" cylindrical shell, suitably modified (no lifting charge bag/cone and a very short delay fuse - mainly to prevent the launch charge from blowing straight through and dismantling the shell before it leaves the tube) and loaded with your smoke composition and (obviously) no bursting charge - vents needed to let the smoke out, of course! Launch with a blank cartridge loaded with coarse grained black powder - one of the "cannon" grades ought to do it, because you don't want high velocity. (Nor anyone downrange of it!) And BE CAREFUL!

It would be completely illegal to produce these in the UK (unless you hold a manufacturing licence, etc.), so don't even think about it. (See the various bits of legislation (Explosives Act(s), Control Of Explosives Regulations, HSE rules, etc.) The quantity required would be commercially uneconomical, including having them made in China, (without considering the UK testing required (at your expense) before they would be allowed into the country).

Pyrotechnic manufacture being a permitted hobby/small business in parts of the USA means that you could probably get something suitable produced in small batches.

Careful testing is essential: some smoke compositions do not play nicely if firmly initiated (or overly contained - even a heap may suffice) and can explode(1). Especially test what happens if the delay element is omitted and the lifting charge blows straight through into the smoke composition!(2)

Chris. (4)
(1) Umpteen(3) years ago we discovered what would happen if theatrical smoke powder was used in excessive quantities (or added to flash powder) - you get more bang than you bargained for and very little smoke.
(2) I recall a 75mm cylinder maroon that went off in the tube, entirely too close to where I was standing, due to the "lift" blowing through or a faulty delay element. I Do Not Want To Experience That Again!
(3) Back in 1984, I think... or possibly 1982.
(4) BPA Level 2, which means I get to do the risk assessments for our displays.

[Jim Burrill]

Great info! All cautions to investigate with our project.

So far..... over here, a smoke pot with no illumination, or noise-bangs is not illegal to have. No license required or storage requirements for home hobbiest quantities.

The licensed part would be getting the BATF tax stamp for a Short Barreled Rifle (SBR) before cutting a shooting SMLE down to the right measurements. We have that sorted.

It may be that a manufactured .303 blank may not have the right charge....pressure, duration, lift... so we may find in testing that we need to hand load some discharger-only blanks.

Obviously, starting with the weakest charge and working up. And with blast shielding and other safety gear on and available during the testing.

It is common here to use No1 SMLEs with the clamp on grenade cup to fire tennis balls using a common blank. Usually blows a hole in the bottom, but not through the ball, so it goes downrange about 150 meters.

While "farby" the yellow balls allow us to police the field for trash after a tactical. We just have to "honor" the strike and either take the hit, or let the umpires note the effect on troops/vehicles. Yes, play acting, but a 100 man tactical event with no logistics trail is not really realistic for a war. But not too bad for a taste of the experiance and keeping safety foremost.

[Larry Mass]

Just wondering if the bracket to mount the smoke discharger to hull is cast, it kinda looks like it on photos. Has any one reproduced these or have an original that they might want to get rid of.
Larry