The athletic / fighting stance
Where the precision rifle lives in prone, the carbine lives on your feet. The default is an athletic, slightly aggressive stance: feet roughly shoulder-width with the support-side foot slightly forward, knees soft, weight forward on the balls of the feet, hips and shoulders squared toward the target, and a slight forward lean from the waist — "nose over toes." This puts your mass behind the rifle so recoil drives into a forward-leaning, athletic base instead of pushing you upright and back.
Avoid the upright, leaning-back posture beginners adopt to "get away" from the recoil — it surrenders recoil control, slows your follow-ups, and collapses the instant you have to move. Think of an athlete ready to move in any direction: that's the carbine stance.
The grip and support hand
The firing hand grips high on the pistol grip, web of the hand up under the tang, with a firm, consistent grip and the trigger finger free to move independently. The support hand does the real recoil-control work. The modern method is to run the support hand well forward on the handguard (within reason — not past your balance point), thumb pointing forward toward the target, gripping firmly and pulling the rifle back into the shoulder pocket. That forward hand position and rearward pull give you leverage over muzzle rise, flattening recoil so the dot or reticle barely moves and returns fast.
Both elbows down and relaxed (not chicken-winged out), shoulders forward. The rifle is clamped between a firm rearward pull from the support hand and the shoulder pocket — solid, but not so tense you tremble.
The mount and cheek weld
Mounting is bringing the rifle up to a consistent, repeatable position against your shoulder and cheek — the carbine equivalent of building a position, done in under a second. The keys are the same shoulder pocket every time, the same cheek weld every time, and a heads-up posture — bring the rifle up to your eyes rather than dropping your head down to the rifle. If your optic height and stock length are right, you mount the rifle with a relaxed, upright head and the dot/reticle is simply there, centered, with full eye relief.
Consistency of mount is consistency of zero and speed. A mount that varies — head dropped one time, cheek higher the next — moves your eye relative to the optic and costs you both accuracy and the instant sight picture that makes a carbine fast. Drill the mount dry until the rifle comes up to the same place and the sight is centered every single time, without hunting for it.
Recoil management and the follow-up
Everything above exists to serve one thing: the dot or reticle lifts slightly on the shot and returns to the target on its own, ready for the next round. A good stance, a hard rearward pull from a forward support hand, and a consistent mount mean recoil is a small, predictable, vertical bounce you can shoot through — not a fight you reset after every shot. When you can call the shot and watch the reticle settle back onto the target without searching, you've built the carbine platform correctly.