I’ve avoiding writing much about the standing position for a few reasons. Chiefly among them was that I am still working on this one myself, and it is my weakest position by a wide margin. Another reason I’ve avoided it is that there really isn’t a single correct way to perform it. There are several variations on the standing, and which one you choose is highly dependent on the circumstances of the shot. Is this a shot taken in CMP-style competition, where stability is more important, or is it taken in a defensive or USPSA style manner in which speed is the priority?
Army TC 3-22.9 has this to say,
This position should be used for closer targets or when time is not available to assume a steadier position such as short range employment. The upper body should be leaned slightly forward to aid in recoil management.
This is the associated diagram of the standing:
This is a pretty standard position for modern rifle combat. The forward lean helps with the recoil and follow-up shots. There is an alternative supporting hand position known as the “c-clamp” that became fashionable some years ago. With that variation, the supporting hand is driven as far out on the handguard as possible and grabs the rifle from the side. The index finger of the support hand is sometimes laid parallel to the bore so that the support hand more or less “points” at the target. This variation is almost always paired with a more squared up shoulder stance and shortened stock.
The touted benefit of the “c-clamp” is that it helps the shooter “drive” the rifle more quickly from target to target at relatively close ranges. It’s not particularly new, honestly. To me, it appears to be an evolution from a stance the Rhodesians adopted for close range shooting with the FAL during the Bush War.
The weakness of this “dynamic” stance is that the rifle is nearly entirely held up with muscle strength. That may work well for situations where speed is more important than precision, but you will begin to fatigue quickly when using this position for long periods of time. In practice, it shouldn’t really be much of a factor for the practical user since you should always be seeking a more stable position than unsupported standing. Unless you are in a defensive situation, where you need to return fire immediately, you will probably have time to find a supported position or take a kneeling/sitting position.
The exception, of course, is when it comes to situations where precision is very important and a more stable position is either impossible or not allowed (as with competition). This stance is characterized by a much more bladed position, the supporting elbow anchored on the support side hip, and supporting the rifle under the handguard (or magazine) wherever it provides the best center of gravity for the shooter. When in this stance, there will sometimes be a distinct rearward lean and a “chicken winging” of the firing side arm. This style permits better support of the rifle by mixing bone into the equation. It is still not perfect, but better than the prior alternative for precision shooting.
Some shooters, who are almost invariably committed to “dynamic” tactical shooting using the c-clamp, will decry anyone using this latter position as an untrained newbie in need of correction. While there are certainly new shooters who will adopt rearward leans due to lack of upper body strength or instruction, it is a very different lean than the ones illustrated above and is clearly much more unstable. If you come across a “tactical” shooter badmouthing the traditional offhand stance, challenge them to a marksmanship match with someone proficient in such a stance…at 200 yards.
Standing is something that requires work and practice. I have a long torso, which means I have trouble resting my elbow on my hip (it’s closer to my lower abdominals). There are other tricks you can do if you are wearing load bearing gear, such as resting the elbow on top of a magazine pouch or some similar anchored object.
Realize that none of the above techniques are the final word. Consider each of them to be tools in the toolbox, with each one having an appropriate time and place for use. Proficiency in each of them, and knowing what works best for your individual body mechanics, will make you the best shooter you can be for any situation that appears.