Center of gravity a factor?

[TurboTrout]

Just was thinking, do bullet makers put any consideration into the c of g of their projectiles?
Would an aft center of gravity increase speed and decrease precision?

 

[Doom]

I suggest you look at this.

Long Range Shooting: External Ballistics - Bullet Shape

Discover the effects of bullet shape in long range shooting with our guide on external ballistics. Improve your accuracy today.

thearmsguide.com

And

Stability and BC

Most things that fly through the air like rockets, missiles, airplanes, etc. use fins to achieve stability. The fins, or tail, move the center of pressure behind the center of gravity. This configuration is known as statically stable. The general definition of stability, as it refers to...

bergerbullets.com

 

[ShtrRdy]

It will affect stability. What do you have in mind?

 

[TurboTrout]

It will affect stability. What do you have in mind?

Just was curious in comparison with aircraft, generally the further aft the CG the better performance but at the cost of less control

 

[Doom]

The following is somewhat simplified. Aircraft stability is determined by center of gravity and center of lift and the forces and moments from control surfaces (rudder, horizontal and vertical stabilizers, ailerons, trim tabs) required to stabilize the resulting forces caused by the differences in those centers.

Bullets have no control surfaces but are spin stabilized. There is almost no lift component acting on the bullet. The primary forces are gravity and drag. These forces are 90 degrees apart and theoretically do not interact initially. However any outside force that acts on the bullet or imbalances in the bullet have no correcting force and the bullet destabilizes. By spinning the bullet it behaves like a spinning top and tends to correct itself if disturbed. (Spinning the bullet does introduce a new force that results in what is referred to as spin drift).

 

[ShtrRdy]

The following is somewhat simplified. Aircraft stability is determined by center of gravity and center of lift and the forces and moments from control surfaces (rudder, horizontal and vertical stabilizers, ailerons, trim tabs) required to stabilize the resulting forces caused by the differences in those centers.

Bullets have no control surfaces but are spin stabilized. There is almost no lift component acting on the bullet. The primary forces are gravity and drag. These forces are 90 degrees apart and theoretically do not interact initially. However any outside force that acts on the bullet or imbalances in the bullet have no correcting force and the bullet destabilizes. By spinning the bullet it behaves like a spinning top and tends to correct itself if disturbed. (Spinning the bullet does introduce a new force that results in what is referred to as spin drift).

I know virtually nothing about this topic but I read a description from Bryan Litz that talked about Center of Pressure vs Center of Gravity. COP can increase the destabilizing affect the further forward it is.

 

[Doom]

That’s correct. In theory the COP and CG are in the longitudinal axis and with the forces at 90 degrees would not interact. However any perturbation will affect that alignment and the greater the distance between COP and CG the greater the effect. As soon as the bullet leaves the barrel gravity applies a downward force at the CG with causes the CG and COP to no longer align and wants to create an overturning moment. The rotational spin counteracts that effect.