What spec for sniper leveling?

Just leveled a IA advanced class Sniper and was wondering what is the fastest and best way to level to 50. I like to do FPs and PVP. But mainly focus on going to hit 50 asap with a leveling spec. once I hit 50 I will spec PVE. thanks

I have a level 48 sniper and have found the marksmanship spec to be good for both leveling and PVE.

This is a link to my build on TorHead.
http://www.torhead.com/skill-calc#400rkrbdosRGRZruM.2

Hope this helps

I levelled as Marks then swapped to Engi as soon as i was able to get Plasma Probe. Roll marks so you can easily 1 shot those mobs

For leveling, MM is a really good spec. If youpair yourself with a DPS companion, you will melt enemies before your health gets much of a scratch. It has really high burst damage, so elites get destroyed. The only issue I had with MM leveling was the weaker AOE damage. Single target you are a monster. I'm not saying you will get destroyed by group mobs, it's just not as easy as with Lethality's poisons or Engi's clusters.

For PvP, I would strongly suggest lethality. The biggest issue with MM is the mobility, and lethality solves that. You cna use most of your skills on the run where as MM you have to be in cover. MM might be intriguing for PvP because of the high burst, but overall, you can get much more DPS because of your poisons.

Ok, hate to be pedantic, because you're technically correct, but engineering's cluser bombs do not help with aoe damage. In fact, they do the exact opposite, because they're for single target damage, not AoE.

Engineering does, however, get bonus crit damage on AoE attacks, a reduced cooldown on frag grenade, and plasma probe. Gotta love that interrogation/plasma/headshot combo.