Ron, it does appear that what you have pictured are shot cartridges for the Crosman Trapmaster Model 1100 which was introduced in 1968.
I have a DBI book titled: AIR GUN DIGEST by Robert Beeman published in 1977. Chapter 8: THE AIR SHOTGUNS (Pg.104-109) has reference to Crosman’s 1100 air shotgun.
“The Model 1100 Crosman had a one-stroke side-cocking single-shot action with a .380 true cylinder bore”.
“The shot container held about one-seventh of an ounce - 62.0 grains - of what the carton identified as No. 8 shot. However, Grennell compared the shot from one of the shells with standard specifications and found that it came out at more like No. 8-1/2 shot, each pellet being about .086-inch in diameter.”
“The literature supplied at the time by the manufacturer stated that each shotshell - that’s what they called them - contained ‘over fifty-five’ chilled lead shot. However, when we broke one of them down and counted out the pellets one at a time, we found that there were sixty-two pellets, making the weight about one grain each. Again, this conformed to specifications midway between No. 8 and No. 9 shot.”
“The shotshell had an intergral over-shot wad held in place by four thin strands of some type of plastic, which was supposed to break away the moment the CO2 pwer was released. A skirted sealing wad beneath the shot charge served the dual purpose of retaining the charge and preventing any leakage of gas as the charge was accelerated down the barrel.”
In the article, there is a picture of the 1100 with it’s breech open with a shotshell partially in the breech and several shotshells, all sitting on top of its box. On the front of the box at the top is the number “2” incide a circle inside the letter “C” with SKEET next to it. Below it states:
100
SHOT
SHELLS
.380ga./no.8s
The picture, being black & white, doesn’t afford much detail of the shotshells sitting on top of the box, but they do resemble those shotshells that you posted above.
I hope this info may be of use to you.
Respectfully.