Borchardt's # I have 505-535-2923 ..

28ga cases are made by Rocky Mtn Cartridge,
Barrel is rifled with 4 grooves, 1-22 twist.
You could do one on Savage 210.Another
shotgun bolt action that would handle it
with little work, heavy barrel, is the
395-495-595-695 bolt action Mossberg.
Just show that 28GA FH isn't puny, here is
picture of it next to a 505 Gibbs.Ed