1) gain access to paradise falls
2) get bad enough karma so that a slaver will randomly approach you with "your cut"
3) now that you know what he looks like you can repeatedly engage him in coversation for more random items such as ammo or meds...etc.
4) Repeat as needed , you can get several hundreds of each ammo , and stimpaks etc. for absolutely no charge.
5) sell the rest that you won't use for a great amount of caps.


NOTE :

I did this for 30 minutes and received around 500 5.56mm ammo , 200 10mm ammo , 200 5mm ammo , 100 shotgun shells , 100 .32 ammo , 50 .44 ammo , 50 .308 ammo , and 100 stimpaks.

Since the items given to you are random , you will get several food supplies and nuka-colas that you will probably have to sell , good news is that with a large amount of these items , you can rack up a nice amount of caps.

You will need bad karma in order for the slaver to appear , if not then very bad karma.

If you have a follower they can help carry some stuff , since you will probably have too much to sell , and you will probably empty out the clinic and "lock n' load". (this depends on how long you perform this glitch).

Since the Slaver will appear on numerous occasions , you can repeat this glitch many times , allowing you to have an infinite amount of free ammo , and stimpaks , as long as you keep a bad or very bad karma.