A friend of mine pretty much destroyed a No. 4 Mk 1 Enfield by shooting several surplus .303 rounds out of a box of 20 he had gotten at a gun show. They had Arabic markings on the headstamp and were extremely hot. One of the locking lugs on the bolt was cracked off and he was very lucky that he didn't get the whole bolt assembly back in his face!
Apparently they were loaded specially for either the Hotchkiss or Lewis machine guns of WW-1 and the markings on the box (after I had them translated) said for machine gun use only.
He gave me the rest of them as "show and tell" items for my reloading classes.
I pulled all the bullets (174 grain FMJ flat base) and discovered the cartridges were loaded with cordite. There was a cork wad between the base of the bullet and the top of the cordite sticks.
I now have lots of cordite to show to people, most of whom have never even heard of the stuff, let alone seen it.
One stick burns very slowly (would create pretty high pressures when fired).
Looks like 2" or so pieces of off-colored nylon monofilament fishing line.
I seriously doubt there is any published reloading data on cordite of any kind and for that reason alone, it would be very bad juju to even consider using it to load your own ammo with. Especially if you value your eyes and other useful appendages.
.