Best bet for the double penetrating unkempt harold is the torgue dlc, it shows up as one of the items of the day.
There are 8 Torgue vending machines in the dlc- you can make it to all 8 within the 20 minute time frame of the Item of the Day (unless you took the Marcus quest item over Moxxie's Heart Breaker). I usually do Pyro Pete's Bar first, the 2 in the Beatdown next, then the Badass Crater Bar, then the Forge, Southern Raceway, the one in the crater just before you get to the entrance to the Forge and then the one in the Arena last. This should make it so that you only have to wait a minute or so before the items recycle to the next set of items and by saving and quitting in either the Arena or Pete's Bar you can start from right next to a vending machine...
I got my level 72 DPUH from the machine in Moxxi's Crater Bar, and I used the Save & Reload method. I tried Pete's Bar first, but that one seemed to be stuck on a rotation of Flakkers, KerBlasters, and Rolling Thunder grenades. The machine in Moxxi's Crater Bar was on a rotation of UH's, Nukems, and Flakkers. It finally popped the DPUH about the 9th or 10th time reloading. . --- What's the purpose in owning a Grenade Launcher? The sheer inability to continue life without it ! ! !
If you're going down the sniping tree OP, why did you not add any points to Killer?
My Zero build is geared toward pretty much any weapon type as well as melee. But I think the reason I have an easier time is because I use a Legendary Killer mod and a Shadow of the Seraphs relic to bring Two Fang at a 90% chance. With that I actually prefer a non DP Unkempt Harold because I feel like a waste more ammo when I'm not entirely accurate. Two Fang in a way makes any non DP Harold into a DPUH.
Anyways I would go put points in Killer and get a Slag Pimpernel. All of your problems should go away so long as you get one. --- Why would anyone ever be a cannibal so long as pizza exists?
I found sniping in uvhm useless. I gave him a pistol build with yes, infinities. I have all elements added with Magic Missle and I've never looked back. BORE BORE BORE. One shot one kill.
Lol sniping is one of the most powerful things you can do with zero. Dont listen to this. Tc you really need to learn how to use zero and study his skills some more of the bees the only way you are doing decent damage. Zero can destroy with so many different weaponz. Just like all the characters.