I'm currently using:
ash tail coat
ash tail cap
wise owlite shield
tempered calibur
cryotech alchemer
rock salt bomb
I've got an avenger and graviton bomb that i can switch in. I've tried various combinations and no matter how i try i can't run tier 2 even though tier 1 is a walk in the park with this gear. Any advice on improvements would be appreciated.
If you've got all that and you're still dying in T2, I don't think it's your gear letting you down.
Mixing guns, swords and bombs can be somewhat challenging. Since you're running ash tail, you should probably stick with a multi-sword setup, and also look at getting yourself some (more) 4* blades. You'll also want to branch out into different damage lines, picking the most appropriate two for a given stratum. (unless you unlock extra weapon slots, in which case feel free to carry all three)
I think the usual recommendation (in 4 star form) is something along the lines of:
Dark Thorn Blade or Grand Flourish for piercing.
Blizzbrand, Boltbrand or Avenger for elemental. (Blazebrand is also nice, but less useful for FSC, which seems to be everyone's endgame obsession)
Silent Nightblade for shadow.
Take a moment to study the damage weakness/resistance types on the wiki. Pay attention to the resistances first so you know which swords *not* to use, then work on memorizing weaknesses so you can optimize your DPS.
Also pay attention to attack patterns and learn when to run and when to shield. Do everything you can to avoid just tanking hits, because you won't last long doing so.