I think you may be reading the headstamp on the blank round incorrectly. Any chance of taking a picture using the macro feature on your camera? That will allow you to take close up photos clearly.
It APPEARS to be a .30-06. If it is, it's an M1909 blank (Jim is correct that it's a blank, and is not for grenade launching), but I can't tell who made it without being able to see the headstamp. The information you provided doesn't match up with anything with which I'm familiar.
Word of warning... NEVER EVER try to use the powder out of an old military blank for anything. Jim's also correct that it won't stand restriction.
The powder used was EC Blank Powder. It was an unbelievably fast nitro powder that was actually used as a filling for grenades during World War II.
EC, like many other flash powders, can be sensitive to shock. It's a lot more stable than some of the chlorate based flash powders, but you don't want to abuse it.
The clipped ammo is most likely 7x57 Spanish Mauser. The case dimensions are correct.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.
Last edited by Mike Irwin; May 1, 2013 at 09:13 AM.