Let's say I run a legal, and legit business and want to start selling firearm accessories.  What can I sell without a FFL?  I know holsters, lights&lasers, add ons like grips, buttstocks, etc but what about internal parts such as triggers, bolts, etc and mags and ammo?  Thanks in advance.

A "gun" has a serial number.

You'd be ok with accessories. You could even sell uppers, but no lowers.

The above post is correct (to the best of my knowledge), but I'll add a couple of minor caveats:

1.  Just because you can sell something in a retail/mail-order store, doesn't mean you can EXPORT it without a license.  ITAR and other export control laws apply even to silly things sometimes, like red dot sights and some stocks.

2.  Always be aware that your State may have laws which are more restrictive than Federal law.  It is entirely possible to have State and/or Local laws restricting the sales of Barrels, Folding/Collapsing Stocks, etc.

3.  ALWAYS check with a knowledgeable lawyer when opening a business to sell to the public.  The fees can be enormous for them to research the laws that might be applicable to you, but the price is tiny compared to what you'll pay them later when you violate some unknown statute.

Good Luck!

FluxPrism

 
Good points FluxPrism.  

I would have never even considered sending anything overseas.  Gonna keep it in the U.S.

I will check state and local regulations.  I don't think I'll have any problems tho I live in a unincorprated part of the county.

Already have given some thought to a lawyer's advice.  I'm still not sure if I'm going to get into selling or not but if I do I'm deff going to see my lawyer.