Guns 1 and 3 are your only keepers. I personally think Gun 1 is better for PvP as it has extra stability without sacrificing anything. Plus it has bonus damage and the chance to restore health after getting a kill. Gun 3 is good but you would have to land headshots like crazy for Triple Tap to be worth it. The perk almost never plays a factors in PvP and is much more suited to PvE. Sure Third Eye is great, but not necessary. And it has no extra stability. Personally Gun 3 is better for PvE and Gun 1 for PvP...but that's just how I would play it. Either one could be effective in either situation. So definitely keep those 2. Gotta admit I'm kind of jealous.

I voted Gun 6 for PvP only, zen moment + field scout + third eye will be doing just fine without any stability perk, and all these perks you can & are using it all the time. Use it more and you can actually control the recoil pretty easily. Not saying your choice of Gun 3 is poor, unless you could consistently land the headshot, go for it! I'm a lazy aimer by the way… For PvE and PvP (general all round performance) it will be Gun 4, and I assume that is the one sold by Lord Saladin. Pair it the 3rd scope optics (TrueSight IS) and braced frame it is pretty solid weapon but at the cost of lower mag of 12 rounds for PvP. Use field scout perk for that larger magazine when doing PvE activities such as the raid. These are my opinions, what matters most is which one do you like the best. If you really want to try out, buy the primary weapon telemetry from Gunsmith, level them up and test it. (A very expensive option with motes of light, but you could do it by cashing in all daily crucible and vanguard bounties.) Cheers!

Soooo You got five drops and still purchased the vendor gun? Too many legendary marks huh?