Question for the experts: factoring bullet weight and sect. density for penetration

[saturno_v]

A simple question

Let's take 2 bullets made of same material and similar shape.
For example 2 hardcast flat nose bullets, one .30 cal rifle bullet 170 grains (i.e. from a 30-30) and one .45 caliber handgun bullet 300 grains (let's say from a 454 Casull)

Let's assume both hit the same target/material with the same energy, for example, 1500 ft/lb.

The handgun bullet is heavier but it has worse sectional density than the rifle bullet.

What is the bullet that will likely penetrate the most and why???


I know that maybe is too simplistic, other factors should be considered, but what is the rule of thumb here??

Thanks!!

 

[Ol` Joe]

The bullet with the higher SD at equal or greater velocity will penitrate deepest. Energy doesn`t mean much here, the wider diameter of the 45 will have more drag on the bullet slowing it. Keep in mind too, the bullets can deforn on contact and the SD will then change. This is why spitzer SP bullets don`t dig as deep as spitzer FMJ. Expansion in a bullet has the same effect as a drag chute on a race car.

 

[saturno_v]

The bullet with the higher SD at equal or greater velocity will penitrate deepest. Energy doesn`t mean much here, the wider diameter of the 45 will have more drag on the bullet slowing it. Keep in mind too, the bullets can deforn on contact and the SD will then change. This is why spitzer SP bullets don`t dig as deep as spitzer FMJ. Expansion in a bullet has the same effect as a drag chute on a race car.

That's why to make things simple for the comparison my example mentions two hardcast bullets that should not suffer from deformation...

 

[rangerruck]

all things being equal after the hit occurs, the 3030 will penetrate further.