I have two sniping classes:
Dedicated Sniper - The ideal dedicated sniper class. Extremely deadly from mid-long ranges.
Aggressive Sniper - Good for sniping on the run and quick-scoping from close-mid range. Everything is fast and furious with this class.
I'm not sure which one is my favorite, but the second one is definitely fun to play and handy in many different types of situations.
When I use the military sniper, I only view it as a sidearm to my revolver. I'm not a very good technical sniper, so I try to compensate this by not having too much of a sniper's mindset. The revolver is my main weapon, and I only use the military sniper when I encounter a situation where my revolver can't help me.
I use covert training 3 since I don't want the enemy team to know that I have a sniper. I find that having an element of surprise increases the chances of getting a headshot. Also, not shooting too much with the loud military sniper reduces the enemy's situational awareness, which in turn results to people running out in the open more often and not buying armor.
The second perk I use is sharpshooter 2, which has helped me tremendously in my aiming ability. I find that using sharpshooter 2 over crafter 3 is worth it since its quality outweighs crafter 3's quantity of giving you more parts. This is especially true if you have no problem falling back on the revolver once the military sniper ammo runs out.