Yes, unfortunately low resolution image
"The illustration of shotshell load is the exact size of a proof test load used in testing Davis gun barrels for strength. The long 3" shell is nearly filled with a special proof test powder and the extra heavy shot load is enclosed in parchment paper capsule..."
Stan: But...but...but Sporting Life
, May 7, 1910
“Stringing of a Charge”
The “stringing of a charge” a subject that has been tested and studied and thought over at great length by all shooters and makers of guns and ammunition, had a unique and apparently successful test recently in England. Mr. Webster Watts, an English sportsman whose shooting ability has placed him in the front rank of English gunners, made the experiments at Brooklands track, the famous auto speedway, near London. Mr. Watts set out to discover whether the charge from a cartridge “strings” when fired at a moving object – that is, whether the last shots, or the slower traveling shots, go off in a sugar-loaf pattern.
Mr. Watts used a big automobile (which ran at speeds of 30, 40, 50 and 60 miles an hour), the sides of which had a big iron target affixed thereto. At a range of 30 to 40 yards Mr. Watts fired, and no matter at what speed the car was traveling, there was not the slightest sign of stringing, in each instance the shots making practically a circle, the reason being that a shot from a gun travels at anything over 500 miles an hour, whereas a driven partridge never, or very rarely, exceeds 40 miles an hour.American Rifleman
, November 1979
“The Effect of a Shot String” by Ed Lowryhttp://www.trapshooters.com/threads/the-effect-of-a-shot-string-by-ed-lowry.58089/