Unknown maker 8 bore


Who made this shot shell? top card simply marked 2

The casing is made by Remington-UMC.
Curtis

Curtis is correct & you will also find this same headstamp style (& color paper, but dark red [yours] or brick red) in other gauges. 10, 12, 16, 20, 24, 28, 32 / 14mm & 410 /12mm.
Also some with low and high base variations.