Yep, I must have picked it up from Vault 34 my first time through, and I've already finished the Vault 22 Quest and HELIOS One. Any ideas how I can finish Veronica's quest? I have no idea where the Pulse Gun could be.

If you have not killed them yet, the Van Graffs can occasionally sell a pulse gun. You can reset their inventory by parking outside their cell and waiting 73 hours, then reentering.

If you brought Boone/Cassidy/Veronica into V34, check their inventory, they are well known unique item thieves..

Especially boone.

I was with Boone and he doesn't have it and the Van Graffs are gone. Stinks.

can't you try and do another quest. there are three things you can do for her.

If you have the C-finder you should be able to complete her quest.

Check were you store items,then check companions hurry and check all vendors just in case you sold it some were.

do you have a quest marker to follow?

The problem is if you set Helios I to power vegas then the C-Finder is no longer an option. If Keely wipes the data in Vault 22 then you can't do it. That happened to me. Luckily I hadn't been to Vault 34. Good luck.