The APS CAM870 AOW is a tactical version of the M870 short, from this brand A shorter version was even possible? Yes, and this is the example.

A shotgun with CO2 cartridges that will fly every time you throw back the slide. You really need to know more?

- Velocity: 250 FPS (0.2g BB) / Range: 30-50 Feet
- Barrel Length: 20 Inches / 50 cm
- Magazine Capacity: 12 Rounds per Shell
- Shell Capacity: 6 + 1
Features:
- Realistic Weight, Feel, and Action
- Real Wood Stock & Grip
- Full Metal Construction
- Realistic Shell Ejection
- 2 Shells Included

And if the list of features and what you have been told is not enough here's this video to convince you to finish: