Since it is not possible to tell the difference in the defense of the gunslinger gear it is difficult to determine the best method of attack. I can make guesses at what they would be wearing but there is not a way to be sure without attacking. It is the only gear I can think of with one appearance and multiple types of defense.
Retexture gunslinger gear
Kentard says it like it is. Nameless is pretty much Justifier with some extra lines on it.
Deadshot also has larger 'cuffs', besides the more obvious skull on the back and missing spurs (Deadshot is also the only set that doesn't have spurs).
~Sev
Nameless also uses your personal color differently from justifier. (e.g. if you're red, different parts of the armour will be red.)
There are only two different models for Gunslinger hats, making it very difficult to tell which one someone is wearing. There's the dark grey hat and the white hat with the crest thing on it. The white one could be one of four different hats (Gunslinger, Sunset, Justifier, Deadshot); the grey could be one of two (Shadowsun, Nameless).
I think it's easy enough to tell the difference between the armor pieces, though.
Well, there's about three threads advocating a reskinning, and I think that it does deserve some attention.
That being said though, I guess it's logical to assume that the defences you wear for the armor would mirror the hat.
There are some very easy ways to tell common gunner sets though:
- Full Justifier. Defends against toothpickers, and probably the most prolific. Counter with elemental/shadow.
- Full Shadowsun. Not Likely to be used as it lacks elemental and pierce defences; since there's a lot of those weapons around in PvP you'll rarely see a full Shadowsunner, and the hat is an obvious shade of black.
- Nameless Hat - Brown. Shouldn't be too hard to spot; although you might have some trouble discerning it from Shadowsun.
- Deadshot - Hard to tell against Justifier; but if you see that starry hat just use elemental. Can't go wrong.
I take it you're referring to Lockdown?
There is a difference in Gunslinger gear, actually.
Shadowsun is pretty obvious given its dark coloration; you can use anything but shadow against that.
Same applies to Deadshot; it's most obvious characteristic is the huge skull on the back of the armor.
Nameless is a bit tricky to tell apart from Justifier, but Justifier has a more plain design on the armor as compared to the Nameless Poncho incorporating intricate white embroidery.
As a general rule though, I suspect most gunners would arm themselves with the Justifier set for PVP so as to defend against prolific Flourish strikers.