Gunslingers, please elaborate on the shield! You use it or not? You die or not? Whats your loadout?
Swiftstrike buckler
As a gunslinger, you normally find yourself quite far away from any enemy so the monster without ranged attacks won't be able to attack you (at least this is how I feel). Definitely take it to T1 and T2 (maybe not Dark City or IMF) and take it to T3 only when the level is something like Aurora Isles Jelly Farm (I and II) or Treasure Vault (actually you don't even need a shield in the Treasure Vault) which is really relaxing and easy. But even then, lots of pros use Swiftstrike in T3.
Get a good UV on it and it really is a very good shield.
I'd think that a good UV on the swiftstrike wouldn't help much. It's not so much the lack of defense as it is the lack of heatlh that makes the shield weak. Your average 5* shield has enough health to take 3-4 hits from damage types it doesn't defend against at all, but I don't see a hypothetical swiftstrike with three choice max UVs being much better than no UVs at all. But I could be wrong; I'm still not too strong with UV mechanics.
Swiftstrike is a shield which should be used only by players that has played long enough to predict enemy attacks. A skilled swiftstrike user shield-bash his/her way through dungeons. The high ASI provided from it makes you able to shield-cancel faster and move after attacking.
I use swiftstrike buckler some times in fsc, mostly with vog cub, swords and guns. although a combo using half namless half vog gives ultra ASI on both swords and guns. the con is once the shield breaks, you cant shield-bash and it only takes 1-2 hit(s) from any enemy for it to break.
The swiftstrike buckler is an excellent shield for anyone who doesn't ever use their shield.
Personally, I use my shield quite a bit, both for bumping and for the whole not dying thing. So swiftstrike buckler is really not an option, as much as I would like to use it.
Swiftstrike buckler set would be something like:
Nameless/Justifier
Armor of your choice!
Swiftstrike
Trueshot
Trueshot
It would also even make Shadowsun worth considering. Ultra ASI+damage on all guns is a pretty nice deal.
Could be nice in tier 1 and anywhere you aren't at all worried about dying, though.