The Mantis Blackbeard the Auto-Resetting Trigger System could be used to assist in Bore sighting your optics, however, the laser will only activate when the trigger is pulled leaving the laser visible for only a split second. This would make it more difficult to boresight your optics. I would just recommend using a laser training cartridge to boresight, and this trigger system for training.
https://www.opticsplanet.com/laserlyte-laser-trainer-cartridge-223-lt-223.html
The Mantis Blackbeard the Auto-Resetting Trigger System will be compatible with your Colt AR15, as well as any Milspec AR15 pattern rifle.
The Mantis Blackbeard the Auto-Resetting Trigger System for AR-15 will work with a piston driven AR15.
The Mantis X Blackbeard the Auto-Resetting Trigger System will work with a left handed AR15. However, the adjustment screws and laser on an off switch will not be accessible.
Please email us at techsales@opticsplanet.com regarding your question with the Mantis X Blackbeard the Auto-Resetting Trigger System for AR-15.
Since the manufacturer states the Mantis X Blackbeard the Auto-Resetting Trigger System for AR-15 will not work in a Saint Victor Rifle I wouldn't try it. I recommend contacting the manufacturer to confirm.
No, this Mantis X Blackbeard the Auto-Resetting Trigger System is designed to fit AR15 magwells, not AR10/SR25 magwells. And includes a Blackbeard Bolt Carrier Group (for DI and Piston driven AR-15).
Yes, the Mantis X Blackbeard the Auto-Resetting Trigger System for AR-15 will work in left handed AR15's.
The Mantis X Blackbeard the Auto-Resetting Trigger System for AR-15 could be used with AR15's chambered in cartridges other than 5.56. According to the manufacturer the system does not interface with the chamber so there should be an issue with AR15's in other cartridges than 5.56 as long as the AR has Mil-Spec dimensions.
The Mantis X Blackbeard the Auto-Resetting Trigger System for AR-15 IR model only has an IR laser. So you would only be able to use it with Night Vision.