Test Gun: Webley Mk V Revolver.
Barrel length: 6 inches.
Ammunition: Kynoch .455 Mark VI 265gr FMJ.
Test media: 10% Clear Ballistics Gel.
Distance: 10 feet.
Chronograph: Caldwell Ballistic Precision Chronograph G2.
Five shot velocity average: 559fps
Gel Temperature 72 degrees.
If I remember correctly I bought this round back in 1987 at a gun store in Minnesota. I thought it was interesting and for the price of 50 cents I figured, why not. The history of this round started in 1891 as the Mk I and went through several changes until the Mk VI which was introduced in 1939.
This round was produced by Kynoch Limited in 1942 using smokeless powder. Some were made with Cordite at the time. If you want to know more about the .455 round this web page has a bunch of info about its history. https://cartridgecollectors.org/?page=introduction-to-455-cartridges
The revolver used was a borrowed Webley Mk V with a six-inch barrel.
With fingers crossed that the chronograph would pick up the round, I lined up the sights at the block of gel at 10 feet. Slowly squeezing the trigger the round went off and hit the middle of the block. The velocity was 559fps for a whopping 184 foot-pounds of energy. The bullet penetrated to 18.5 inches and was recovered base forward. There was very little disruption in the wound track other than about midpoint showing evidence of it tumbling. The recovered weight was 264.7 grains.