It'll be a great mistake to replace the Ultimax 100 as our
standard SAW. The Ultimax is already a very good weapon in itself.
It's not much of a stretch to say that foreign weapons experts
practically worship our weapon.
Heck, the US Army is thinking of getting the newest Mk IV as their
standard LMG. Lazer, do you remember which thread I'm talking
about? Ok if you could post a link to that thread? 
As any SAR 21 user knows, reloading a bullpup is a major pain in
the ass. If you're going to fire at full auto, then you'll find
yourself cursing and swearing at having to change the magazine
every twenty seconds. Even if they come out with a 100-round drum
mag for the SAR-21 LMG, I can imagine that reloading is still gonna
be a major hassle.
I say just adopt the Ultimax 100 Mk IV version and forget about the
SAR 21 LMG. I see no point in trying to change a good thing.
