The biggest reason for a poor shot is a terrible firing position. The kick alone will be enough to jostle you off target and can even knock your weapon from your hand. The best position to fire a rifle is the in the prone.
The primary benefits are limited involuntary movements because your entire body is in contact with the ground. In order to maximize these positions effectiveness, try to balance the rifle on a sandbag or use the magazine to create an additional point of contact with the ground. The cons include taking a long time to get into position and leaving your movements inhibited. The prone position is great when you know where the enemy is and you do not have to worry about being taken by surprise.
Many people think of the prone as the position for snipers, but truthfully it is the most accurate position for any rifle. You do not need a fancy scope to get the benefits out of this position. In fact, it is advised that you practice with iron sights as it eliminates the crutch that magnification offers. Anyone can shot a rifle if the target looks like it is five feet in front of you, but only the best can hit a dime at a hundred meters. Overall, the prone position is great when you know where the enemy is and you do not have to worry about being taken by surprise.
Kneeling is probably the best all-around position if you are wanting to fire a weapon in a tactical situation. While it does not offer the long-range stability of the prone, it does allow a versatile way to engage, bu giving you the freedom to transition between pieces of cover like windows and from vehicle hoods.
To the untrained, it will become clear that kneeling will tire the muscles in your shoulders though this is a sign that you are holding your weapon incorrectly. Tuck your elbows close to your chest as it will make it easier to hold a rifle. Instead of resting the bony part of your elbow against your knee, lean forward a bit more and rest your tricep on your kneecap. If you are flexible enough, you will find that pressing your chest against your knee will provide additional stability. The final aspect of this position is your feet. Instead of resting your knee on the ground try to mimic the picture in how the Soldier rests their weight on their leg rather than a single point of contact. This position is not perfect for everyone and in the end, you need to be comfortable. If you are fighting your body, you will not be able to take accurate shots.
Once you are in position, you will notice that your sights will naturally move in a figure-eight position. This means you are doing it right. You do not want to struggle against your weapon and try to keep it center on your target at all times. Instead, wait until your sights pass onto the center portion of the figure-eight and understand that the center part of the movement is actually where you will be firing.
The last and most commonly used firing position is standing. The problem with this is that it offers little support and easily results in wild shots. In order to maximize its effectiveness, hold the foregrip of your rifle with the “C-Grip” and press against some form of cover. This strategy can be combined with any of the other positions, though it is crucial to the standing position if you are wanting to take an accurate shot.
While standing is a bit sloppy when it comes to actual marksmanship, it makes its bread and butter from being highly mobile. Standing is the only position in which you can fire while you move. If you are not behind cover and you feel the need to fire, remember that it is not actually about making a great shot. You will want to fire as much as you can so that the enemy will keep their heads down while you are en route to your next piece of cover or concealment.
Try to think of it like a shotgun. Every pellet will not hit the target, but the fact that several will spray out will increase the chances that at least one will find their target. The same strategy can be used with rifles. Aim in the general direction and pull the trigger. While it is likely that many of the rounds will miss, it is possible that you will get lucky and one will find its mark.
With some range time, it will be easy to determine your personal nuances of each position. This is intended as a baseline in which you can start your marksmanship training with focus rather than simply wasting rounds.