@Formidilosus
What are your essential checks for getting stable on seated shots over a pack? Ie hand positions, shoulder connection, is the rifle resting on your shoulder as you pull it in or is your hand mostly holding it up as you tuck it into your shoulder?
The shot process is the same from all positions-
1). Body position: Straight and neutral behind the gun, as low as you can get, with as many contact points as you can get. Support front first, then rear.
2). Breath control: Breath in, breath out, bottom of the respiratory pause.
3). Trigger control: Smooth and continues movement to the rear until the trigger breaks at 90°.
4). Reset and prep: See bullet impact/splash, vigorously, but controlled- rack the bolt, start back over at #2, and prep for follow up shots.
As for interfacing with the rifle; positive control. For rested positions, generally the rifle goes where it needs to, then the shooter moves as needed to control and support it.
Grip pressure is neutral but firm (about enough hold the rifle muzzle up with just the firing grip), shoulder pressure is about what the rifle weighs (8’ish pounds), or on rifles with heavy recoil- about as much as the recoil itself.
Face/cheek pressure is firm, but not smashed (let head drop fully onto cheek rest, then lift up about 1/8” to 1/4”.
Off hand controls rear of butt- usually by pinching with the thumb and forefinger.
I/we deviate quite a bit from the current PRS thoughts of as little contact as possible, basically no cheek weld, buttpad center of chest, etc.
That works fine for static targets, and where the shooter can get directly behind the rifle- I.E., tripods and contrived range positions. On targets that move, under stressors- excitement/time/cold/wet/tired; rifles that move, etc. it is not optimal.