Smokeless Powder instead of BP for Ejection Charges

[Right Wing Wacko]

Has any one here experimented with or used Smokeless Powder instead of BP for ejection charges?

As a Re-Loader I have several shelves full of various types of Smokeless Powder, and it seems to me that if the differences between SP and BP can be compensated for, it should actually be superior to BP for deployment charges.

Differences:

1. Easier to obtain and store.
2. Requires a hotter ignition source (Similar to Composite Motors)
3. SP burns better when under pressure. (under ideal conditions it is much cleaner than BP)

Are there any regulatory issues that I am not aware of? It is my understanding that SP is less regulated than BP

[CarVac]

You actually want it to burn better when not under pressure, or else there could be potentially greatly reduced ejection force. That's one if the issues with Pyrodex.

[Eric1]

Red Dot works fine. Wouldn't waste my rifle powders though.

[karlbaum]

Smokeless powder can be used. I have read about people testing it. CarVac is absolutely correct. I have used Pyrodex a lot and it has to be contained. I use 1/2 inch vinyl tube and hot glue the ends shut.

[Windeavor]

I had some Green Dot on hand for shotgun reloading that I tested in my copper pipe ejection charge tubes. These tests were performed outside and not in the rocket body tubes. Powder was packed in tight with enviro-green insulation (bale from Lowes) and electrical tape on top and e-matches. Charge went off ok but there was lots of unburned powder laying around. Not sure if Red Dot burns better but my immediate concern was the unburned powder acting like projectiles and could end up doing damage to the chute.

I ordered some Graf and Sons FFFFH BP and man what a difference. No issue with unburned power in my setup, but the down side is the soot. I have no problem with a little soot as long as the powder does its job. I actually like all the smoke it produces as it is much easier to see the events going off when the rocket is out of sight. I run separate charges with 2 sec delay at apogee which makes a nice cloud of smoke that is easier to spot at higher altitude.

[bobkrech]

Wb References for smokeless recovery.

Going Smokeless!

Smokeless Powder in Simulated Rocket Recovery Ejection Systems

Both references are reasonably complete summaries of the pitfalls of smokeless power ejection systems.

1. Only use fast burning pistol and shot gun powders. Rifle powders generally burn too slow.
2. High pressure confinement is necessary to obtain complete combustion.
3. Easy of ignitiblity is important fo fast combustion rate
   
   • BF > Pyrodex(R) > Triple Seven > Pistols and Shotgun powder > Rifle Powder
   • Even BP requires confinment over 20 kft.
   
   
4. BP and BP substitutes have metal contain oxidizers that leave non-volitile corossive combustion products behind.
5. Smokeless oiwders burn out completely at high pressure to gaseous products: Ideally to water, carbon dioxide, and nitrogen.

Bob

[grouch]

From my black powder shooting days I seem to recall that BP leaves 50 percent mass of the original charge behind in residue. That's why it is important to swab out the barrel on tight bores like 32 Cal. Kinda makes me miss my old smoke poles.

[Right Wing Wacko]

One of things that makes Pyrodex a bad choice is that it is a Smokeless Powder that has been mixed with fillers so that it's volume equivilent with BP. This leaves a lot of inert non-combustable powder as part of the mix. It would seem to me if one was going to get away from BP, Pyrodex would be the Last thing you would want to use. If one is going to go with SP, go with a true SP, not an SP pretending to be BP.

As stated, one would want to use a fast burning powder. Bullseye would probably be good, but I'm also thinking of Tite-Wad or Clays Shotgun powder instead. Containment is the issue that concerns me the most. SP requires higher pressures to burn completly, however when it does so, there is very little residue when compared to BP.

I'm thinking of testing used Rifle Shells or perhaps Shotgun Shells. Perhaps the igniter wires can be routed thru a drilled primer pocket? A wax or soft rubber plug could be used to seal the top of the cartridge.

[Larry Curcio]

Has any one here experimented with or used Smokeless Powder instead of BP for ejection charges?

As a Re-Loader I have several shelves full of various types of Smokeless Powder, and it seems to me that if the differences between SP and BP can be compensated for, it should actually be superior to BP for deployment charges.

Differences:

1. Easier to obtain and store.
2. Requires a hotter ignition source (Similar to Composite Motors)
3. SP burns better when under pressure. (under ideal conditions it is much cleaner than BP)

Are there any regulatory issues that I am not aware of? It is my understanding that SP is less regulated than BP

Or even flash paper (nitrocellulose), sold in magic shops. This stuff produces a report in a PVC tube without wadding. It can be stored when slightly damp. It burns cleanly, and is, in fact, a constrituent of SP.

Never tried it...

[bobkrech]

One of things that makes Pyrodex a bad choice is that it is a Smokeless Powder that has been mixed with fillers so that it's volume equivalent with BP. This leaves a lot of inert non-combustible powder as part of the mix. It would seem to me if one was going to get away from BP, Pyrodex would be the Last thing you would want to use. If one is going to go with SP, go with a true SP, not an SP pretending to be BP.

As stated, one would want to use a fast burning powder. Bullseye would probably be good, but I'm also thinking of Tite-Wad or Clays Shotgun powder instead. Containment is the issue that concerns me the most. SP requires higher pressures to burn completely, however when it does so, there is very little residue when compared to BP.

I'm thinking of testing used Rifle Shells or perhaps Shotgun Shells. Perhaps the igniter wires can be routed thru a drilled primer pocket? A wax or soft rubber plug could be used to seal the top of the cartridge.

Wacko

Pyrodex(R) does not contain any nitrocellulose, AKA smokeless powder or single-base. Here's the MSDS. It is simply a modified BP with less sulfur and a second, more powerful oxidizer. It contains no inert fillers. It is less sensitive than BP and harder to ignite because it has less sulfur. Nitrocellulose, or single-base smokeless powder, is sensitive and harder to ignite than Pyrodex(R), however it is more energetic and make only gaseous products when it combusts. Double-base smokeless powder contains nitroglycerin in addition to nitrocellulose to increase the energy per unit weight. Higher energy smokeless powders have several percent of additives that reduce barrel erosion, fouling and lubricate the bore. None are inert fillers.

Pyrodex(R) and smokeless powders have slower characteristic linear burn rates, but the particle size still regulates the gas production rate. Spherical powders burn the fastest the gas generation rate of any solid propellant is proportional to the burning surface area. Equal weights of smaller diameter particles have more surface area per unit weight than large diameter particles, and since the characteristic linear burn rate is composition and pressure dependent, the greater the surface area, and the greater confinement, the faster the hot gas production rate. The gas generation rate of BP get slower as the grain size gets coarser (larger), so the gas generation rate of FFFFg > FFFg > FFg > Fg. The relative burn rates of Hodgdon smokeless powers are listed here.

Bob

[fyrwrxz]

Thanks Bob- you saved me a boat load of typing (and fixing same-I'm terrible on a keyboard).
While I'm not encouraging anyone to make their own bp, alternatives such as crimson powder, golden powder and grey shot are a lot more labour intensive and need tp be made ahead of time in small batches. CO2 based systems work extremely well, esp for higher altitude flites and there is no residue. One thing to consider is your ignition system for your charges. make sure you are using a 'sensitive' e-match your timer or altimeter can fire faultlessly. I'll have to admit, my eyes are getting older (just my eyes- I have the body of a 25 year old Adonis-lol) and I went from wrapping/soldering my own to the MF wires from Quickburst and have been very pleased with them at 100%. All the PerfectFlights, RRC2, and Adepts I have fire these off fine. It would be best just to go ahead and get a LEUP (Alley-Oop) and find somebody with a storage magazine your can get an agreement with to enable you to hold/use BP in your rocketry work. Having said that Pyrodex works fine with containment and no license is required. Straight smoke and good chutes!

[Tarasdad]

I've been a reloader for over 30 years for everything from handguns to shotguns to high-power rifles. Been a Muzzleloading enthusiast for just as long, if not longer. When it comes to the uses we are discussing here (generating sufficient pressure to deploy our recovery devices) I feel much safer using FFFF BP than trying to engineer a system to use smokeless propellants.

[cdw.lighting]

I use pyrodex because I could not find BP. I use the drink straws from Starbucks(they have a large diameter). I fold the end, tape with vinyl tape, put in half the charge, install the match(q2g2 ignitor), fill with remaining charge, fold over end and wrap the whole thing in vinyl tape. So far I have had no recovery failures, although with everything dual Deploy, GROUND TEST GROUND TEST GROUND TEST!!!!!!