This was a proprietary round developed by James Purdey & Sons around 1922 and was made by shortening the 450 3¼” case to 2.70” necking down to accept a .375 cal. bullet. All hammerless Purdey rifles are rare, with production of under 450 in all grades and calibers since 1880. Factory records indicate that the rifle shown here that was listed on invaluable.com was made for the proprietary .369 Purdey cartridge, developed to compete with Holland’s 375 Flanged Magnum.