We used to buy rimfire versions of our centerfire arms to save money while training. .22 LR ammunition has been so scarce lately that LaserLyte has come out with a trainer for your trainer.
The LT-LR is designed to fit inside the barrel of firearms chambered in .22 LR (or .22 Short, .22 WMR or .22 Long, for that matter) and, using the sound of the hammer or striker, produces a red laser dot to simulate bullet impact. The LT-LR can be used with barrels as short as 1.875 inches, so it should function even in rimfire versions of the Smith & Wesson J-frame or Ruger LCR.
When used in conjunction with LaserLyte's Reaction Tyme Targets or Trainer Target Plinking Cans, what would normally be repetitive dry-firing exercises can be fun plinking training or even reactive shooting time. The rimfire laser trainer lets you practice bullseye shooting with your high end .22 LR pistol or steel challenge with your semi-automatic rifle.