wiley coyote is good.
As to looking up the effects ? I know enough not to want to know, and hope no one ever needs to know.
My " phone a friend's " response -
.50 BMG
20 mm
.577/450 M H
and
.50 BMG
Cut off 50 BMG by appearance
.577/450 MH
I would agree with that but did not recognise the 'cut off' .50 BMG case, as for the .577/450 they originally were made with a thin brass foil and soon after with a brass case.
I'm a bit dim lately.
Looks like some one has a minor case collection.
.50 BMG used in a military machine gun or aircraft WW2 ?
.50 Cut off - trench art? and even possibly as a brass case for a 12gauge shotgun, yes they do fit, it is cut the correct length.
--- .50 BMG have been test fired from shotguns - surprising results.
.577/450 - Boar War era firearms, Snider Rifles, SA Police were issued with them in 1867 from memory, a very modern firearm in those days.
--- Kato found a projectile from one of these in her Grandparents back yard - they were a smooth bore rifle and later improvements changed to a rifle --- bored firearm.