The enemy matters too. Let's face it, one man just doesn't stack up to another. Anybody with 4 hours of training on the counterstrike noob server can take out a dozen somalian insurgents lol
Anyway, you'll want a tokyo marui VSR-10 or L96. Not a clone, not a chinese POS, and nothing gas or AEG. You want a springer, bolt action, tokyo marui rifle.
Good luck finding one, it's not impossible but they're a tad rare.