On line auctions, gun shops, gun shows, pawn shops.
Remington
It is difficult to find even 10 gauge shotgun ammo today. I have my doubts if 8 gauge shotgun ammo is even made any more, but corrections welcomed.
yes
American Gypsies - 2012 Shotgun Wedding 1-8 was released on: USA: 4 September 2012
Remington makes a industrial 8 gauge kiln gun.
I have a Old W. Moore Double Barrell Shotgun 8 ga. with Hammers. 850-742-0288 Don OR 870-565-5985 Larry
p=8 x=3
Market or kiln gun
Shotgun Mythos - 2012 Putting Down the Dog 1-8 was released on: USA: 30 May 2013
Shotgun Slade - 1959 Rail Head at Rampart 2-8 was released on: USA: 5 December 1960
Shotgun Pass - 1931 was released on: USA: 1 November 1931 Portugal: 8 November 1935
a few hundred to multiple thousands depending on the usuals