Here's some info gleamed from a recent shooting clinic. We liked the presentation and decided to repeat it here.
As a silhouette shooter our goal is to put the crosshairs on the animal and break the shot. Our common enemy is wiggle. Nobody is immune from the wiggles, but the better shooter has methods to control it. If we break down all the random movements they are either in the vertical or horizontal direction or a combination of the two. The following techniques are aimed at minimizing movement in the vertical direction.
The best support for our rifle is a solid one. The silhouette rules outlaw rifle supports that don't come standard on the human body. The most solid part of the human body is bone and that is what we will build our rifle support out of. Every human body is different. Each shooter will likely need to tweak and modify these methods to suit his or her body shape.
For right handed shooters it should look something like this. Feet should be shoulder width apart and facing between 45 and 90 degrees to right of target. Place left elbow on left hip. Left forearm extends straight up from hip and supports underside of rifle near middle of action. Right arm pulls rifle into shoulder firm enough to stabilize rifle. Shooter looks through scope and sees dot or crosshairs fall comfortably on target. If it doesn't work this smoothly, keep reading. This is where we start tweaking.
The average shooter usually finds that, in this position of bone supported rifle, the point of aim is low. From here, with muscles in left arm remaining relaxed, we look for changes to find more elevation without using any muscle tension.
Modify your left hand support. The higher the rifle the better. Some techniques rely on muscles in the hand or wrist which may introduce a new source of wiggles. Different hands multiplied by different rifles equals too many options to list. Watch other competitors and experiment to see what works for you. Also, moving the left hand back usually elevates the muzzle. Moving it forward drops the muzzle. This is sometimes used as a fine tune for banks of animals at slightly different heights.
Shifting the hips toward the target can help raise the left side of the hip bone. This will usually get us a little more elevation. Opening our stance a bit, with hips shifted, can gain us a bit more.
If you are having trouble moving the support structure up, you can compensate by moving the butt of the rifle down. This may compromise your cheek weld, but will definitely gain elevation.
Once you find the bone supported structure that works for your model of human body, attempt to duplicate is for every shot. If you have made a substantial change, scores may take a dip in the short term. If your change is to a stance that incorporates more bone support and less muscle support the long term payoff will be worth the short term cost.
