7776 tris is WAY too much, even for a higher poly gun in Q3. I doubt most of the default player models go over 1000. You have too much detail in the scope, and almost no detail in the rest of the gun. There are lots of ways to still make things look round without using thousands of polys. All the guns I've made are under 400 tris, and (not to sound like I'm bragging) have fairly good detail.
When I first started I had some of the same problems, but take this advice from veda:
"Think of it this way, an average Q3 player model is 800 polys. Your gun is 1300+ , you have 5 guys running around with those on screen and now you are drawing 10,000+ polys. The irony is that more than half of those polys are taking up the smallest percentage of the screen in form of the guns."
Just some advice
