AR-15 Trigger Finger Placement on Receiver
I've always placed my trigger finger in "register" along the receiver of an AR-15 in a way that approximately feels like where I place it on a pistol. This ends up with my trigger positioned like this:
http://i913.photobucket.com/albums/a...uff/photo3.jpg
The problem I've had with this placement is that something coming into contact with my right hand (usually the ground) can cause me to accidentally press the magazine release. I've notice that a lot of other shooters use this position:
http://i913.photobucket.com/albums/a...uff/photo2.jpg
But, I don't like how close this is to the trigger guard.
This pretty much leaves only this placement:
http://i913.photobucket.com/albums/a...f/photo1-1.jpg
This feels sort of uncomfortable and my finger ends up on the dust cover when its open, which is weird because I'm used to the register position always feeling the same way and my brain thinks there is something wrong when my trigger finger hits something unexpected. I assume this will go away with practice.
What does everybody else do, and do have you ever had any accidental mag release issues? (It happens for me most often when shooting through the bottom ports of a VTAC barricade.)
AR-15 Trigger Finger Placement on Receiver
I do what is in your second picture. It's not perfect, but I have small hands, and have trouble getting to a register position all the way above the mag release. I count on the contact with the ridge around the mag release button to prevent slippage into the trigger guard, right or wrong.
EDIT: Looking at the picture again, I'm actually slightly different, from what you show. More akin to what Ash described, between the button and the ridge, half contact on each.
AR-15 Trigger Finger Placement on Receiver
BTW (from another thread), aren't you afraid that lower will give your position away?