New Crimped Shotgun Shells (Jul, 1939)
I *think* this is how all shotgun shells are made now…
New Shotgun Shell Aids Skeet Shooters
TRAPSHOOTERS and skeet enthusiasts should improve their scores with the use of a new shotgun shell that is said to eliminate the possibility of fired shot forming a “doughnut” pattern that could encircle a clay target without breaking it. Highspeed photographs like the two at the upper right, taken by the light of a 1/1,000,000-second spark, proved that the top wad at the end of conventional shells occasionally interferes with the charge, causing the inefficient “doughnut” shot pattern. The new shells have no top wad, the open shell mouth being crimped together by a special machine to confine the shot. When fired, the shell mouth unfolds, leaving nothing to obstruct the charge.