If it wasn't for the weight I would say that they are for a 35 cal. BPCR, most likely a 35-40 Maynard, which is a 38-55 case sized down to 35 cal. If cast from most any lead alloy it should 200gr. +
Could be shot out of a pistol cartridge such as a .357 maximum in a TC Contender.
Not likely to be for a smokeless rifle, 35 Whelen, 35 Rem. due to the lack of a gas check.
Interesting
Cliff