Use the +3 damage mod with a scope on its own you have a very powerfull mid game sniper, and keep a fully modded version for more mid range work.
I've got the strangest luck in NV, my latest character I went back to guns for a change, even before I reached primm I've ended up with 2 laser pistols, 2 plasma pistols, a plasma rifle, and a laser RCW all just from the easy areas around Goodsprings, no merchant bought ones either??
Last game I could not get any good stuff, so my advice save before entering any building, and when you loot it, quit to menu and continue.
