Looking for collectible .50 caliber cartridges, 12.7x99, 12.7x76, .50/20mm, .50/.60, etc. Basically anything that throws a .50 caliber projectile or is based on the .50 BMG calilber cartridge case. US or Foreign. Also interested in other Heavy Machine Gun cartridgge of other countries, 12.7x108, 14.5x114, etc. Trade stock available.