Penetration capability: Sectional Density vs. overall bullet weight

[saturno_v]

A simple question for the experts:

If we have two bullets built in the same way (for simplicity sake, let's say solid), same nose shape, same style, one lighter but with higher sectional density and the other of larger caliber, heavier, but with worse SD.
Both strike the same target, from the same angle, with the same energy.....as general rule, which one will penetrate more??

A practical example is a Hornady 454 Casull load flat nose 300 gr which strike at 100 yards with 1210 ft/lb of energy. The same manufacturer offers a 30-30 flat nose 170 gr. load which strike at 100 yards with 1218 ft/lb of energy.

The 454 bullet has a SD of 0.210, the 30-30 bullet has a SD of 0.256

So which one will penetrate further, in theory?? We are not talking about wound channel and other factors...just penetration.

P.S.

These two Hornady loads in reality have different bullet construction, but let's pretend they are both solid in this example.

 

[gvnwst]

The smaller one, higher velocity and better SD make for better penetration.

 

[Runningman]

30-30 bullet

 

[cliffy]

LOOK toward the BONDED bullet

Bonding of lead and copper jacket seems the best of the best! Disintergrating bullets give dubious results. One solid slug with proper expansion appears unbeatable in its destructive force. Demand Bonded Bullets, and it shall swiftly become reality across the board. This technology is now commonplace, so settle NOT for less. cliffy

 

[Dr. Tad Hussein Winslow]

The answer is that weight, ipso facto, has no bearing. Ceteris paribus, the higher SD bullet will penetrate more.

 

[saturno_v]

Thank you guys.

The answer was obvious to me but you did help me win a bet with my range buddy!!!

Thanks again