Yes, Chain Triggers are the main damage source for Gunners it's pretty much what the class is designed around. So here's a few simple tips.
-Use Forward Stylish Roll (L) if you aren't already it makes a big difference. Especially since Gunner gets a ton of bonuses for rolling. It's even more important than Chain Triggers.
-Consider getting Twin Mach. Guns Stylish Charge if you don't have it.
-Get Infinite Storm Zero. This is why you need Twin Mach. Guns Stylish Charge so you can bypass the large charge times.
-The basic combinations use Satellite Aim, Assault Advance, and Infinite Storm Zero.
-Don't try to force 100 on Chains all the time. Sometimes you just have to take whatever you can get, some bosses are like that.
-You can "buffer" Chain Trigger. Basically this is using Chain Trigger and running out the activation window before setting it on a target. This is so you get to your next Chain Trigger faster. This can be during a downtime, stun, or while using PAs.
There's a lot of combos you can do with Chains and an extreme amount of advanced tech like roll canceling and weapon swapping. It can get kind of complicated.
If you want anything for further information I'll leave a top notch guide below. It goes over just about everything.