After WWII, hundreds if not thousands of arrows were made using the jackets intended for .30 caliber rifle bullets. As I recall, they were 10 to 25 cents each, the cheaper arrows
had the nock just cut into the wood, the more expensive had plastic nocks and better feathers., and they were sold as target arrows. I bought and lost a lot of them at that time.
The ones I'm thinking of had a reeded groove around the back, to hold the point on the arrow, and the marks on this find make me think arrow point rather than bullet jacket, although
they don't look exactly as I remember.