William must have borrowed that from that other Greener fella

"Laminated Steel Indestructible By Gunpowder"

Greener pinfire



Greener percussion double



The L.C. Smith listing in the 1908 Sears, Roebuck & Co. Catalogue No. 117 included Bored For Nitro Powder (both Armor and Damascus barrels) and the Notice All our guns are tested with heavy loads and cannot burst except by carelessness, obstruction in the barrel or improper home loaded shells with nitro or dense powder.
That last sentence pretty much says it all.