Suppose we have two identical rifles. The only difference is the way the weight is distributed along the length of the rifles.
Rifle 1: the weight is evenly distributed along the whole length of the rifle.
Rifle 2: the weight is concentrated in the butt plate and the muzzle.
(I know these are impossible to achieve. But just consider this hypothetically.)
Both rifles weigh the same and have the same location of centre of gravity. Will they feel the same on shooting? Will the static stability be different? Will the rifles react differently during the shot and after the shot?
C of G and weight distribution on AR Standing
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Statics was never my strong suit in engineering, but here goes:
My high school physics teacher did a demonstration. He had an empty soda can and a solid cylinder of the same weight. He rolled them side by side down an incline. The solid cylinder reached the bottom faster.
The solid cylinder had a smaller moment of inertia than the soda can. Think in terms of mixing the leverage needed to lift a stick with a weight on the end of it. Then add in the equal pull of gravity and you can see how the solid cylinder will accelerate faster.
On to rifle, the one with equal distribution will have a smaller moment of inertia, and thus will move more with the same force applied to it than the rifle with the weight at the ends. Thus you could consider the rifle with equal distribution to be more reactive to muscle tension and recoil.
Now to get to the rifle's feel in position. This is where I'll get pretty fuzzy, but here goes. The rifle is supported by two points of contact, the fore end and the butt plate (assume minimal support by trigger hand) and assume the CoG is likely located closer to the butt than the muzzle. Then there are 3 possibilities of the support hand: it's at the CoG, in front of the CoG, or behind the CoG.
If it's at the CoG, then the weight distribution will not make a difference in how the rifle feels to the shooter in terms of balance.
If the hand not located at the CoG, the result is the same, the rifle with equal distribution will feel butt heavy and the other will feel barrel heavy. This is because the distance between the CoG and the supporting hand creates a torque on the rifle that must be compensated for by the hand and the shoulder.
I think I got that right for the most part. Someone check my math.
My high school physics teacher did a demonstration. He had an empty soda can and a solid cylinder of the same weight. He rolled them side by side down an incline. The solid cylinder reached the bottom faster.
The solid cylinder had a smaller moment of inertia than the soda can. Think in terms of mixing the leverage needed to lift a stick with a weight on the end of it. Then add in the equal pull of gravity and you can see how the solid cylinder will accelerate faster.
On to rifle, the one with equal distribution will have a smaller moment of inertia, and thus will move more with the same force applied to it than the rifle with the weight at the ends. Thus you could consider the rifle with equal distribution to be more reactive to muscle tension and recoil.
Now to get to the rifle's feel in position. This is where I'll get pretty fuzzy, but here goes. The rifle is supported by two points of contact, the fore end and the butt plate (assume minimal support by trigger hand) and assume the CoG is likely located closer to the butt than the muzzle. Then there are 3 possibilities of the support hand: it's at the CoG, in front of the CoG, or behind the CoG.
If it's at the CoG, then the weight distribution will not make a difference in how the rifle feels to the shooter in terms of balance.
If the hand not located at the CoG, the result is the same, the rifle with equal distribution will feel butt heavy and the other will feel barrel heavy. This is because the distance between the CoG and the supporting hand creates a torque on the rifle that must be compensated for by the hand and the shoulder.
I think I got that right for the most part. Someone check my math.