Spectre Ammunition MFG Co


Can anyone provide information on this company. The test on the following cartridge reads

Spectre Ammunition MFG Co
Special Purpose Ammo (SPA)
Sniper - Countersniper
See Label

It was a single cartridge found in a dig box so I’ve not seen the label.

Bullet is GM with a brass? tip. Case and primer are brass. HS is IMI 308 WIN