When I shoot my secondary weapon (handgun) both eyes are always open – this takes practice – but this is typical for operators who are always aware of conditions in their periphery vision (shoot and move, other threats, aware of other operators, etc).
My grip is the same on my handgun, or any handgun for that matter. While my eyes are on target I grip my weapon, index the weapon as I draw the weapon “up”, then acquire my front sight post while pulling out the slack (usually very little due to trigger job) and shoot.
Experienced operators will typically pull the slack out of the trigger once the weapon is drawn and facing the direction of the target – takes a sh** ton of practice with an experienced trainer – thereby allowing engagement if the threat closes the distance to you.
Grip-1a Hands on Weapon
If gripped correctly, index is the same, and I have clear vision of my front sight, the round surprises me when shot while the slide moves directly to the rear allowing the front sight to drop right back on my point of aim (target).
Been on a firing line lately? Take a step back and scan the shooters while noting the degree of muzzle flip (high left, right, regrouping, slapping the tripper, etc).
Grip-1b Trigger Finger (pad only, pull straight to rear)
All of this takes consistent practice to the tune of 400-500rds per day x 3-4 days a week.
The fundamentals are the same with a rifle albeit the dynamics change when using scoped/powered optic weapons or those with lasers.
Front site focus (everything is else is slightly blurry), site is aligned
Rear site focus (everything is else is slightly blurry), site is aligned
Squeeze (pad only of your index finger on the trigger / left-hand released to allow view of trigger finger)
Here is an idea that is worth gold. When nobody is home I pull out my Glock .40 and clear and safe check the weapon. I then sit on the couch with an empty weapon and dry fire at the various targets that appear on the television. Take a shot, cycle the slide and come right back up on the front sight waiting for the next target, reengage.
Focus on pulling the slack out prior while bring the weapon to bear so that the trigger-sear mechanism is at the edge of “dropping.” Then incorporate mag change drills (empty mags of course).
Hell I’ve even set up various targets around the house with various lighting conditions (moving from dark to light and vice versa) and engage targets as I shoot and move dry fire. Again, this takes practice. Of course, if you have neighbors make sure your blinds are pulled so they don’t get the wrong impression.
Dry firing is absolutely priceless and far more valuable than dry firing at the range…a more realistic environment for me.