For that rifle you will need the CMC Triggers AR-15/AR-10 Duty/Patrol Single Stage Trigger Module small pin.
The difference between the CMC Triggers AR-15/AR-10 Duty/Patrol Single Stage Trigger Module and another CMC Trigger would depend on the specific CMC Trigger you are asking about. However, these CMC Triggers AR-15/AR-10 Duty/Patrol Single Stage Trigger Modules are all preset from the factory with a pull weight of 4.5lbs.
The CMC Triggers AR-15/AR-10 Duty/Patrol Single Stage Trigger might work in a Sig 716i. CMC Triggers states that the CMC Triggers AR-15/AR-10 Duty/Patrol Single Stage Trigger will work in Mil-Spec Dimension AR15's and AR10's. I recommend contacting CMC Triggers to confirm compatibility.
Yes it should be compatible.
We do not recommend modification to your firearm to make a product work, these triggers use the standard pin size, if you are unsure of what your lower receiver has, I would contact the manufacture and ask before purchase.
They should be able to work no problem together.
These are 4.5lbs triggers.
These are 4.5lbs triggers.
The difference is the physical diameter of the pins. Small pins are approximately .154 diameter while large are .169. If you lower receiver was manufactured by Colt between the years of 1991-2009 it may use a large pin trigger. If you lower receiver is not Colt or was manufactured outside of those years then it will use a small pin trigger.
Yes, this trigger will work in a DPMS .308 lower receiver.