I'm working on an ammo project, and I'm trying to make everything reasonable. Right now, I'm working on AP rounds. So I did a little snooping in GECK and found the following ranges of DT values:

(Type | min | avg | max)
Clothing | 0 | 2 | 5
Light: | 0 | 8 | 16
Medium | 10 | 15 | 20
Heavy: | 15 | 26 | 36

This includes matching helmets.

So, given this information, I'm trying to figure out what makes sense for AP ammunition. What I have currently is that all AP ammunition gives a damage multiplier of 90%. The DT modifier is arranged thus:

6: .22LR, 9mm - all clothing, some light
8: 10mm, .357 magnum - all clothing, most light
10: .44 magnum, 12.7mm - all clothing, most light, some medium
12: 5mm, 5.56mm - all clothing, most light, some medium
15: .308, all clothing, almost all light, most medium
20: .50BMG - all clothing, light and medium, some heavy

I also have SLAP (saboted light armor penetrator) ammo for both .308 and .50BMG, giving DT bonuses of 25 and 40 respectively. These rounds give 80% damage multiplier for balance.

So, given the above DT information, for armor, are the values I have picked out reasonable and useful? Most AP in vanilla gives -15 DT and 95% damage bonus, regardless of cartridge. I thought a sliding scale depending on cartridge would make more sense. But I think the values I picked may be a little light. What do you think? Is 90% damage too steep a penalty? Do you think maybe DT should stay fixed, but damage should change? Or maybe a little of both?