So, in Goodsprings, I talk to Chet and he says he can Mod my weapons yet he has no mods in his inventory nor a dialog option to mod weapons (he just describes what mods do). What am I missing here?

ive only seen one for a revolver drum upgrade, they are in the misc section.

Get to level 2 and mill about Goodsprings for a while. Chet will eventually stock a night scope for the Varmint Rifle. You buy it, and voila--modified. I think.

He had a Varmint Rifle Silencer in my game, but that's all.

If you buy the weapon mod it isn't automatically installed. To install it you simply need to go into your inventory, highlight the weapon you wish to mod, and press the left bumper if you are on the 360, then select the mod to apply.

EDIT: Also you can find weapon mods from most weapon traders, not just Chet.

Thanks. I guess I just to check back with him on occasion. I was a little worried it was a glitch or something.