I accidently came into ownership of some of this ammo. Box is marked: .30 SEC PLASTIC M64. Date code is Lot 1 ASM 69. Headstamped F N 62. Ammo is brass cased 30/06 with an opaque plastic round nose bullet shaped somewhat like a 110 gr. plinker round. They come in blue 10 rd boxes and 7 of the boxes are still sealed. I have never seen them before and was wondering about collectibility/value or should I just go shot them up?? Thanks