I need to find some ammo for the Ycs 186 weapon . I have gone to many different vendors but they don't have this ammo listed? I would appreciate any help on this subject thank you Torgue1

Isn't that the unique gauss rifle? If so it will take microfusion cells. Since I found it that is my favourite weapon, I'm doing an energy weapon build next time just for that. Tip - if you can, make some max charge microfusion cells, it ups your single shot damage a huge amount.

Get in the good books with the BoS by completing their first quest, then the little goody two shoes BoS trainees will leave a supply of recycled power cells of all types in a container at the BoS bunker for you.
You want to go to Silver Rush in freeside to get your energy weapon needs as well.
And of course, loot, loot and Loot some more.

The 186 with 100 in energy weapons, Max Charge MF cells and a hint of psycho is the god button.

Tbf I hit the level cap with less than 35 in energy weapons, and with the Max Charge cells the 186 is STILL pretty much the god button Not that I'm complaining mind you, if I were that worried about game balance I could put it in a container at some far flung spot and forget about it, nothing is forcing me to use it...

i have thousands of microfusion cells at all times, first of all you need to go to the good merchants, the great khan armory has a merchant who sells lots of ammo, gunrunners, also contreras at camp macarren, trading post 188, just establish all the merchants, also you can convert energy cells and electron packs to microfusion cells, so just buy some of those and convert them, thirdly use other weapons so you aren't using too much ammo of one type. hope that helps.