Cartridges that are loaded with cordite?

[ETG]

Hi, All.
I have been searching these posts and the internet to find an equivalent load to 14gns of 360 No. 5 cordite. I think it may be easier to try to find some cartridges that are loaded with cordite than finding an equivalent load. I recently acquired a Greener Martini light harpoon gun. Tonight I got the harpoons, lines, and line holders. I read it used a Greener specific 38 Special blank. I happened to have a 38 blank crimper from a 37mm project. I crimped a 38 special and it fit in perfectly. I was reading that some 303 British are loaded with cordite. Does anyone know what years it would have to be or any other cartridges/sources of cordite?
Thanks,
ETG

[deces]

I found a loaded 303 round while out picking up brass once, upon pulling the bullet, viola... Cordite!
I'm under the impression its from around the world wars era.

[Kosh75287]

I'm confused. What cartridge actually is loaded in the chamber? Is it a .303 case, modified to accept the base of a .38 Special case where its primer pocket WAS?
If yes, then there's an old load used to push cast bullets of usual weights (like ~150 gr. for .30 cal) to ~1500 f/s in MOST military service rounds, which MAY work or provide you with a point at which to begin. This combination consists of 13.0 - 13.5/Red Dot/150 - 180 gr. Cast LRN. It is known as "The Load" in many of the circles of cast bullet enthusiasts.
Now, for YOUR purposes, it sounds like you'll need to omit the projectile. Not being familiar with how the harpoon fits to the chamber, I have no idea of what pressure level is "okay" in the harpoon launcher. With this in mind (and assuming you have no other information to fill in the gaps), I suggest you cut your starting charges to about 1/2 what I've related above, and work up in 0.5 - 1.0 gr. increments. My suggested 6.5/Red Dot/"VERY MASSIVE HARPOON" starting load may not develop enough pressure to move the harpoon fully away from the "rifle". But it is also unlikely to damage it.
If the rifle is rated to use Cordite-based ammo, it should be okay with low doses of shotgun powder. In fact, if your "projectile" was a 150 gr. bullet, I wouldn't be writing such a cautionary epistle. But when the "payload" goes from a ~1/3rd oz. cast lead bullet to what is essentially a "flying brick", chamber/barrel pressures can do weird things, fast.

You MAY even find that "The Load" does not develop enough "oomph" to launch the harpoon any distance. If you find that this is the case, then you may need to "step up the game" a bit, and use very fast-burning rifle propellants like IMR/H4198, or Alliant Reloder-7. With these, I'd again consult a trusted reference on cast-bullet rifle loads with "typical for caliber" bullet weights.

If you don't mind, I'D like to hear about your results, as your experimentation progresses.

Best of Luck!

[gunther]

Might do a little research to see just when this particular Greener was developed. It might be designed to use black powder as an alternative. The Greener company goes way back, and harpooning is/was rough work, and the supply lines are/were pretty sketchy. The gun may have been designed to use whatever was available.

[Kosh75287]

Might do a little research to see just when this particular Greener was developed. It might be designed to use black powder as an alternative. The Greener company goes way back, and harpooning is/was rough work, and the supply lines are/were pretty sketchy. The gun may have been designed to use whatever was available.

Entirely possible, and an excellent point. I think I dismissed this possibility because of the corrosion liability. But if the darned thing was designed to be used at sea...

[ETG]

Kosh75287, the rifle is chambered for a 38 Special with a load of 14gns of 360 No. 5 cordite. I mentioned 303 British because I had read in several post that people had pulled them down and they were loaded with Cordite. The harpoon slides over the barrel not in it (see attached pic). Supposedly Germany with all their strict gun laws considers this a toy because it does not expel anything out of the barrel. Wonder what ATF would think? As for projectile weight think more like 7,000gn - a pound. Greener claims it is effective out to 30 meters. The chamber is 38 Special but the barrel it is a smooth bore of approximately 25 cal. The barrel is considerably thick up to where the harpoon slides on. There is no manufacture information on it and it doesn't appear to have been used. All the lines look new and the harpoons are not scratched or dinged. The auction I bought it from listed it as a 22LR. It looked odd and I knew nobody would use a recoil pad like that on a 22. I got it a couple of months ago. The harpoons, line holders, and lines showed up on the same auction site under the same estate sale so I was able to get them. They also had a double barrel shotgun barrel and a rifle stock scattered through the auctions. Pulled the pictures up in a photo program and the barrels was a from a CVA 50cal EXPRESS double rifle and the stock was the rest of the gun Sorry, I got side tracked. I love it these people have no idea about guns. Some were just listed as a 48" gun - nothing else. Anyway, I was trying to figure out how to load up some cartridges for the Martini. A projectile that heave would really take some oomph to be lethal at 30 meters. Any better ideas than to try to find some old cordite from a British cartridge?
Thanks,
ETG

[45workhorse]

Bales of hay, pumpkins, water melons. Be kind of neat to see it shot. Might want to lock it up Friday, and Saturday night!

[ETG]

Hay is what I was planning to use. First would be shot off a lead sled with a string

[ETG]

Hummmmm - might want to sit out on the front porch with it!

[samari46]

Used to live on Long Island NY, one of the gun shops used to have a cased Greener harpoon gun. Gun, harpoons, lines and one box of special 38 special blanks that came with it. Frank

[15meter]

There is a Reloder 15 conversion formula used for the old English double rifles that literally had their load stamped in the rifle. The load that was stamped was the load that "regulated".

Double rifles are designed so that both barrels hit to point of aim at a specific distance, hence the term regulated. It is always a challenge to get them to regulate with other powders and bullet weights.

The formula does seem to work pretty well. I just loaded up 8 rounds of 450-400 with Woodleigh's and RL-15 last night to verify that they do indeed group under an inch an a half at 50 yards.

Minute of cape buffalo accuracy.

I always assumed there were different cordites available, this is the first time I have seen reference to a specific grade of cordite. The only cordite I've seen is from .303 British. I've got several ounces sitting on the bench that came from .303's that I broke down. Buddy and I have joked about reloading some with non-corrosive primers just to give it a try. Just haven't figured out how to get that spaghetti back in the case.

And I believe that cordite was used from the late 1800's through at least the 1950's if not into the 60's.

[ETG]

I have read that the 303 was loaded with cordite into the early 60s. I'll try to find some. I have a hard time imagining a load in a 38 Special blank that would propel that harpoon 30 meters with still enough force to spear a big fish.

[uscra112]

Ignore that post about Red Dot. Fast powders produce high pressures when pushing a heavy load.

No idea where to get burn data for cordite, but that used in the .303 would have to be somewhere in the neighborhood of 4895, I would guess. And that's ONLY a guess. Look in loading manuals for data for the .303 and pick the slowest powder recommended.

[john.k]

More than one type of cordite was used in 303s.........the kind used with the Mk6 bullet is similar to 4198 in load and velocity......the Mk 7 cordite load was also supplemented by an IMR load for the same velocity,and less bore wear in MGs..........the powder used was IMR4740........not available ,but very similar to IMR 3031.

[john.k]

Incidentally,other than 303 used cordite too,the Sniders used cordite tape (tapeite?),but generally pistol cartridges used Ballistite ,which is a fine grain double base powder similar to shotgun powders.........cordite was a very stable propellant ,used in up to 16" guns as long bundles of pasta like material .

[Milky Duck]

There is a Reloder 15 conversion formula used for the old English double rifles that literally had their load stamped in the rifle. The load that was stamped was the load that "regulated".

Double rifles are designed so that both barrels hit to point of aim at a specific distance, hence the term regulated. It is always a challenge to get them to regulate with other powders and bullet weights.

The formula does seem to work pretty well. I just loaded up 8 rounds of 450-400 with Woodleigh's and RL-15 last night to verify that they do indeed group under an inch an a half at 50 yards.

Minute of cape buffalo accuracy.

I always assumed there were different cordites available, this is the first time I have seen reference to a specific grade of cordite. The only cordite I've seen is from .303 British. I've got several ounces sitting on the bench that came from .303's that I broke down. Buddy and I have joked about reloading some with non-corrosive primers just to give it a try. Just haven't figured out how to get that spaghetti back in the case.

And I believe that cordite was used from the late 1800's through at least the 1950's if not into the 60's.

now this I can answer..the cordite was cut to correct stick length and stacked into the .303 british case that WAS THEN FORMED.....so the cordite was poked into basically a straight walled case that was then squished in to form body taper and neck....
personally I believe you could do a lot worse than try a case fulled with black powder...not sure if would need a wad under crimp... but you could make some up and let them rip without payload to begin with.

[beechbum444]

I have to ask if that was the gun used in Jaws???? very cool

[uscra112]

The spools of cordite were kept behind a firewall. The strand(s) were led through a small hole to the women doing the cutting and filling. The hole had a guillotine blade that cut the cord and blocked the hole if there were ever a fire. There's a picture of this in a WW2 American Rifleman. I'm sure I still have it, but don't ask me to find it now.

[Bmi48219]

There’s a reason rubber band powered spear guns are supposed to be fired under water. If the target is missed the water resistance slows the spear to avoid breaking the lanyard. Don’t know if that applies to Greener Harpoon Rifles too.

Good score ETG.

[Thumbcocker]

Some Pakistani .303 was loaded with cordite until more or less recently. 1950's or 60's IIR .