Phil...I Hollis (not to be confused with A. Hollis!) was primarily a gun trade military contractor and manufacturer of "trade quality" shotguns for the British Colonies - just about every Australian would have an uncle or grandfather that had a Hollis (or Cashmore etc) under the bed or behind the wardrobe. But, I Hollis also made some pretty high grade guns and double rifles - I had one in "your" calibre (450/400 31/4 inch) once, a very high grade, game scene engraved, ejector model. Shot extremely well with "Australian" loads (i.e. 83 grains IMR 4831/Federal 215 primer/400 grain Woodleigh SP pills/Bell cases - pressure approx 10.9 ton/sq. in. and velocity around 2050 fps) For light "Plinking" loads, you can use .40 cal pistol bullets - I used 220 grain Speers with 40 grains SR 4759 powder, Fed 215 primer, for 2145 fps - shot parallel, but a but high in my gun.