The Colt Challenger was introduced in May of 1950.  It would be be in production until 1955 where it would be ultimately replaced by the Colt Huntsman model.

The Colt Huntsman is a 22LR caliber semi-automatic pistol with a detachable magazine.  It started production in 1955 and ran until 1977.  The Colt Huntsman was a fixed sight pistol that Colt brought to market to help compete with some of the other low cost alternatives available at the time.  The Colt Huntsman was available in 4-1/2" and 6" barrels.