Modern Body Armor

[Rupert]

Originally Posted by wikisteff

Fascinating thread, Icelander and team!

Does this mean that AP rounds shouldn't actually have Armor Divisors in the real world? Should we just step-up AP damage to make up for it? Does GURPS maybe need an (1.5) Armor Divisor step to better fit real-world data?

(Sorry for resurrecting an old thread, first-time poster here.)

In the real world AP small arms ammo doesn't really do a whole lot less damage to living things than ball does, nor does it have double the penetration. In the game basic AP rounds do much less damage (70% of the basic damage, and a smaller damage type as well), and penetrate about 40% better. Not reducing damage type for it would probably be fair when comparing to ball. However, that then makes APHC do less injury than cheap 'basic' AP, and that's not right, so it needs to not have reduced damage type either. It would probably be reasonable to only reduce damage type on AP rounds that use a dart plus discarding sabot (i.e. modern anti-tank AP rounds), and even then only on quite small ones (which really means only the few APDS rounds used in autocannons and HMGs).

When it comes to heavy weapons, there isn't really any kind of armour that's universally 'hardened'. There are plenty of AP rounds that should have penetration modifiers of various levels to reflect that they penetrate armour better than they do injury, relative to a basic solid shell ('ball' in small arms). There are types of armour that are effectively hardened against specific types of shell, however (but this can also be reflected by just giving that armour more DR vs that attack). For example, heavy warship armour in the late 19th to mid-20th century was face-hardened specifically to ruin APs rounds, but it didn't improve its resistance to non-AP rounds. Of course the AP rounds were then improved to resist the anti-AP properties of hardening...