引用自 SilverWind：

-No damage
+On hit: Marked for death for 10 seconds

In other words, a Jarate SMG.

Thats a bit too much, the jarate has a long cooldown, thats why the amount of "marked for death"
I would say:
+On-hit: Marked for death and slowdown for 5 sec.
-90% damege penalty

How about instead of Jarate, it outlines the enemy that was shot, allowing you to track whomever you shot if they decide to run away, I.E. a Spy who decided that this Sniper was a bit quick on the uptake this time and wants to come back later.

No damage, or at least minimal damage, and a smaller clip. the Paint can wear off after.. 15 seconds?

This will allow snipers to be able to paint targets and track them for a short period of time and line up shots where they couldn't before.

引用自 Rockabunny：

How about instead of Jarate, it outlines the enemy that was shot, allowing you to track whomever you shot if they decide to run away, I.E. a Spy who decided that this Sniper was a bit quick on the uptake this time and wants to come back later.

No damage, or at least minimal damage, and a smaller clip. the Paint can wear off after.. 15 seconds?

This will allow snipers to be able to paint targets and track them for a short period of time and line up shots where they couldn't before.

I like the marking idea. Have a large clip but downside of very little damage like even less then the carbine. Would be good for team mates too assisting or pointing out a enemy in the back row that may of snuck back.