3&1/4dr 1&1/4oz 1225fps Italian nickel-plated load with pic of cute little pigeon in flight on the case develops about 9425psi of gas pressure. Oh, since HS CD is an American load don't hesitate to tag on 900-1000 psi to that lovely figure.
What exactly is their definition of 'Classic Double'? Gee, I hope your gun is ca. early 1930s to mid-1930s in excellent condition and has original 70mm chambers.