I'm at level 22 and the only thing I have seen is a couple of mods for sale at the gunrunners. I remember an article before the game came out showing pictures of guns with different stocks and that you can mod them in three different ways. The only scope I have come across is one for the varment rifle.

When you wait for three days, the stock will rotate. The first time you go there, there will be some low level stuff like Varmint Rifle mags, and Pistol scopes. When you come back and as you level up, eventually you'll find every single Gun there, but the mods will still rotate, I'm level 30 and there's Sniper Rifle silencers, Mini Gun frames, 200 round LMG drums, so just keep coming back or wait in front of the store.

ghost digga lol lvl 30 im like 19, anyway ive seen a range of mods and at gunnrunners the .50 cal has just apperared

I actually didn't... 'get' to level 30 I just sort of... was... :ninja:

I can buy some cool mods from Gun Runners.