which endorsement would be better for gunner?

lvl1 fire rate+ or lvl1 critical+ ?

Probably fire rate, he doesnt need crit rate, its high enough when hes deployed at lvl 2 and has dual mini gun.

My build is: Gold- accuracy. Silver- Clip Size. Bronze- Reload Speed.

Out of those choices definitely rate of fire. I wouldn't suggest crit for any build of any class, but that's just me. There are too many other good choices for every class that are guaranteed to help you, rather than relying on rng.

I actually use crit on assault and use silver accuracy and bronze rate of fire. Since assault already has a really high crit rate with both his passives, it makes for an interesting build XD.

This is what i use for my gunner.

Fire Rate (gold)
Clip Sise (silver)
Reload Speed (bronze)

Accuracy (gold) virtually every bullet hits
reload speed (silver) like that you just get the reload done quickly.
speed,clip size,skill regeneration(bronze) i like all 3 of these but i normally use speed.

I always run the same silver and bronze.
I use

Silver- Accuracy
Bronze- Reload Speed

For gold, I switch between armor and rate of fire. RoF leads to a more glass cannon playstyle, but is very good in certain situations. Lastly, I have a class with gold speed so I can get to the ball in overtime.

fire rate is one of the best endorsements

meh i still use armor as my gold i dont like getting 1 shotted by assassins

maybe they tweaked something recently.. I was playing gunner with gold armor just 20 minutes ago, and assassins still 1-shotted me

I go Clip size\ROF\Armour

Clip size on Gold is just pure rape with Gunner. You can mow down an entire team without ever needing to reload, twice! When delpoyed it's even better because even the tougher enemies like Tank or other gunner who should probably be able to out-gun you and you just keep on shooting and taking hits and beat them both.

Epic.