Grade 1 = "decarbonized" steel barrels (not Damascus). Any experts on these? I am mainly planning to shoot brass shotshells loaded with Alliant Black MZ at 2 1/2 to 3 drams and an ounce to 1 1/4 shot. But I'm wondering if the B&P low pressure shells I use in my old Ithaca Flues are OK. My Ithaca is 1921. This one is circa 1900.