by78
General
Why is the last one shorter?
I think it’s a .338 Norma casing for comparison.
If accurate from long to short the 8.6mm class would be .338 Lupua magnum at 8.6x70mm, 8.6 Chinese at 8.6x65mm. Then .338 Norma magnum in 8.6x63mm along with 338-06/.338 Winchester magnum. And at the bottom With 8.6x43mm Blackout. There are are probably a dozen more obscure wildcat cartridges here but simplicities sake.
The shorter one is the casing for the machine gun round. See here for more info.