I'm not sure if this is a bug, an exploit, or a frame-perfect, fighting game-style "working as intended". Anyway, here we go:

Under the correct conditions, it is possible for a Machinist, when using Gauss Barrel, to get a free usage of Enhanced Slug Shot or Cleaner Shot... but without consuming the buff. The conditions for this have to be absolutely perfect, and are as follows:

1: The Machinist has to cast either Split Shot or Slug Shot.
2: Before waiting to see if Enhanced Slug Shot or Cleaner Shot, respectively, appear, immediately start to cast Slug or Clean Shot.
3: If, and only if, the timing was absolutely perfect, then the Machinist will be about 0.1 to 0.3 seconds into the cast of Slug or Clean Shot when the buff appears... and then can start to move without cancelling the cast. More importantly is what comes next.
4: Immediately after completing the cast, which will either hit at 180 or 200 potency depending on whether Slug Shot or Clean Shot was used, the Machinist can use Slug Shot or Clean Shot at 180 or 200 potency, again, because the game did not consume the buff upon the first, casted Slug/Clean shot's hit.

I tested this multiple times. When it worked right, I could have my then-55 Machinist (she's 56 now, huzzah!) toss out a pair of critical hit Clean Shots (thank you RNGesus) at between 980 and 1060 damage each, in a total of about 1.43 seconds, according to my Skill Speed stat. This provides even more burst damage capacity than proper usage of Raging Strikes, B4B, Ammo, Wildfire, Rapid Fire, and Reassemble in the proper order (EDIT: which I didn't put them in, my bad!), since this can work regardless of ammo usage or not. It's all on RNG, and if you get lucky, you can be tossing out an obscene quantity of high-power abilities. But when it all worked out right, my Machinist popped a high of 2324 on Wildfire. Doing the math, that comes out to 619.7 dps... at level 55.

Under the luckiest circumstance, the following happened, with potency in parentheses:

cast time Split Shot (140) --> cast time Slug Shot (180) --> cast time Clean Shot (200) --> Cleaner Shot (200) with no cast --> Slug Shot (180) with no cast --> Cleaner Shot (200) with no cast

All of this with Gauss Shot and Head Graze liberally mixed in for extra damage. Note that the above is without using ammo or Rapid Fire. NOTE: This bug/exploit/frame-perfect technique does not work if you are using Rapid Fire, and doesn't always work if you have little to no lag.

If this is working as intended, which I highly doubt it is, then Machinists, get ready to play roulette with your Slug and Clean Shot casts, because you'll either start doing ludicrous, heaping sums of damage... or very little at all from all the 100 potency attacks you'll be tossing out to no avail.

If there is any extra information needed, I should be able to provide it. Just not tomorrow; I'm rather busy unfortunately until the evening. Wednesday may or may not be looking better.

Anyways, this is probably a bug, but I thought it'd be best to bring it to the community's attention.

October out.