Item was defective - Laser Ammo SureStrike 9mm Cartridge Laser Trainer

I had high hopes for this 9mm laser cartridge for training. The laser seemed to work fine when the batteries were installed, and pressing the black contact cap with a finger seemed to require a significant push. I tried the laser ammo cartridge in a S&W M&P 2.0 to no avail. Next was a Walther PDP, still not working, moved to my M&P shield plus, but not working. Finally tried it in my CZ Shadow 2, but no joy. The cap must be defective.