Had a gunshow today and got this
The round on the left is .30-06.
The one on the right was a .50 BMG with a 7.5mm hole drilled through the projectile, the rim cut off, and the primer flash hole bored out to 13mm and threaded. The overall length is 121mm, the case length is 94mm, the projectile length from case mouth to projectile tip is 27mm.
Take these measurements with a grain of salt but they should be within 0.5mm.
So any ideas? My thought was to allow a subcaliber blank to be inserted to allow for the functioning of an MG in places where .50 blanks are hard to get?