There is a reason why benchrest shooters use concrete benches to shoot from: they simply do not move. That’s a major factor in how they shoot groups that others only dream about.
At the other end of the scale, there are no simple answers to the problem for the hunter walking a swamp after pigs.
It’s a matter of taking your chances unless there is a convenient log or tree available to provide you with some sighting stability.
The average person standing upright is a quivering mass of human jelly, not a good shooting platform.
The longer the distance, the worse the problem becomes. A sighting error is magnified by the distance involved.
One the most useful accessories in relation to rifle stability for the hunter in the field is a pair of shooting sticks.
If you ever look at a typical African safari on the TV or internet, the professional hunter will almost certainly be carrying a pair of shooting sticks for his client to use when taking the shot.
It seems to me that in Africa the use of shooting sticks is universal.
There are commercial models available but you can make your own out of two pieces of one-inch wooden rod and a piece of used bicycle tubing.
Another useful aid is a bipod, which attaches to the front sling mount of the rifle. I have used them extensively.
You can alter the length and use them on the ground either prone or when sitting. They are also very useful at night when spotlighting.
Usually fitted with rubber feet, they can be used over the roof of a vehicle.
Now tripods are becoming popular, providing even greater stability, especially for standing shots.
Perhaps the most useful accessory we have ever used in our family shooting has to be our portable shooting bench.
It is used on every occasion for load development in conjunction with a front portable rest and rear sandbag. The legs slide off for transport and it is extremely stable.
Again, you can buy portable benches but you can also make one.
Cost is minimal and any tradesman could make one very quickly.
Ours accompanies us on all shooting trips. It is useful when sighing in rifles and provides a stable platform in the field when shooting at long range. A drummer’s adjustable stool provides correct seating.
There’s another aid to stability that is often overlooked: your rifle’s sling.
When wrapped around your forearm, either sitting or standing, it does provide a measure of stability that is better than none at all.
The other shooting position missing in this day and age is sitting with the sling wrapped around the other arm.