6 pounds 11 ounces is not particularly light for a 12 bore built for the British market where loads tend to be relatively light, typically 1 ounce
or 1 1/16 although I anticipate that you will find that your gun was built and will have been British Proofed on importation with 2 3/4” or 70mm chambers.

Parker-Hale were the importers for many years.