Best weapon for Claptrap's "One Last Thing"?

[Osamaru]

Anyone know what the Best weapon for Claptrap's "One Last Thing" skill is? I was thinking the Striker, but I can't find out how low the Mag can get (I know how HIGH it can [4], but not how LOW), or Plunkett. Plunkett is nice, but the problem I have with it is, once you miss that last Crit, you either have to stick with the lower damage, normal crits, or peg something 5 times without Crits till you get to that last bullet again.
Anyone have any suggestions?

For those that do not know, Craptrap's "One Last Thing" increases the damage of the Last bullet in your Mag, but 400% at rank 5, though the boost decreases the lower the Mag size (Min 8 for the full bonus, allthough it is still theoretical 2x damage for a 2 mag gun)

[𝕰𝖑𝖜𝖔𝖔𝖉]

flakker or ravager

[76561198157514419]

explosive guns to make use of claptraps massive explosive buffs
the best shotgun the moonface does explosive damage, has a mag of 3

[Osamaru]

Darn, I was hoping it would not be a Shotgun, Bwahahhaha, Oh well, thanks!.

[cfteague2]

With a shotgun, do you have to get down to 1 bullet left? or does the last shot count?

like say the gun has 4 barrels - 4 shells per shot, and a 14 round clip. when it's full, has 14, first once, has 10, then 6 then 2. Will the skill work, when i fire that final shot? it's not the last bullet in the clip, cause i have 2. but i'm gonna fire both of em in one shot?

[Osamaru]

Its the last shot in the Gun, for exsample, I had one that had 3 rounds and used 3 rounds, so it triggered every Shot. Unfortunately, it was also a Green weapon with a low rof, and a bit underleveled .
But also, keep in mind, this was a Green weapon doing the same DPS as a Striker (though it had 13 pellets). If Someone could find something like this as a High level Purple, it would make every other Weapon in the game look like a Joke.