Only in the larger examples, generally over 6.5". There were numerous failures in the 200 pdr (8") Parrott's, but later analysis indicated that the problem was not with the gun, but the shells. The shells were prematurely detonating in the bore, fracturing the cast iron tube through the breech at the touch-hole. The 300 pdr. (10") Parrotts had similar shell failures, but they tended to blow the muzzle-area of the tubes off rather than the breech. The gunners would simply chisel the fractured areas smooth to permit loading, and continued to fire the massive rifles. In one instance on Morris Island, the muzzle was blown off the 10" Parrott rifle by defective shells three times before the gun was finally too damaged to fire! Gunners in those days were made of very stern stuff!