This is a tiny mod that gives energy weapons some armor penetration. I made it for my own game but thought why not release it, maybe somebody will want it.

http://www.newvegasnexus.com/downloads/file.php?id=38567

The way damage is calculated in NV the multiplier from OC and MC ammo is (afaik) applied after subtracting DT. This makes perfect sense for traditional projectile weapons but not for directed energy guns.

To circumvent this problem OC now divides DT by 1.25, MC by 1.75 (with some rounding inaccuracy).
This leads to the same results as if the damage multipliers were applied before subtracting DT.

I have to admit that this makes plasma rifles and gauss rifles very strong but since ammo is very expensive I think it's acceptable.

This is my first publicly released mod. (And my first attempt since Morrowind) So use at your own risk

Just a heads up- the upcoming patch overhauls the the OC and MC ammo. I'm not sure how this will affect your mod.
# EC/ECP/MC ammo (standard) now has -2 DT
# EC/ECP/MC ammo (over charge) now has -5 DT
# EC/ECP/MC ammo (max charge) now has -10 DT

That patch will make my mod pretty much unnecessary. (So better disable it after patching or it will overwrite the official changes)
I just wanted a change now while I'm still playing and it only cost me like 10 minutes to find out how it works and make the changes.