Well actually I don't have a problem helping you with the weapon... As I've already done a weaponpack. Unfortunately I really lack on time at the moment. So you will have to wait at least untill the end of june.
Animating is no problem.. and Ivan is doing the coding.
That's how the animations look like:
Ivan (fische11) made this video
YouTube - M99
Thats the MK 23 (very very old version.... pre Alpha but it's ok)
YouTube - HK MK23 In-Game Movie
It's a lota fun shooting Zombies in row with that thing.
My Weaponpack contains:
MK. 23
Spas
Barett M99
RGP 7
Desert Eagle
M7A3 (does not exist.. it uses Bullpup design)
But we really have no time port those weapons to KF
(the base code is from the Ballistic Weapons)