When I was a kid, I flew Estes rockets and also had an early reloadable motor - a Jetex. Jetex motors used a loadable pellet, were lit with a fuse, and had their nozzle held in place with a spring that hooked over the end of the motor. Thrust? There wasn't much. From the web, I see the thrust for the standard motor was:
Old aluminum "50" in the 1/2 ounce thrust range = 139mN
Later steel "50" in the 3/4 ounce thrust range = 205mN
I don't know which series motor I had, but suspect it was a "50". I never flew it in an airplane but did put it on several cars. Not very exciting as I remember but, since I like rockets, I thought it was cool. I wish I still had mine.
The best source of information on these motors is Jetex.org.