I was gifted a range bag of goodies, and an old CVA 'Hawken' pistol this spring. I finally got to look through the bag and found about 50 of these monsters.
They measure .504" diameter, are 1.250" long, have a slight bevel base, and weigh a lot over 505 grains, which is the limit of my reloading scales.
I've found similar online but not exactly this one. I've come to think they're for BPCR... any help is appreciated.