Unlim. Ammo. is extremely easy to find. Since you know the basics of how to search with MHS, I'll shorten it. Now, well begin with the basics :
Let's say your Ammo is 40/90 (AK-47 w/ Extended Magazine) you'll add 40 and 90 together. So it'll be 40+90 that'll add up to 130 .
Step 1 :: Search for 130
Step 2 :: Shoot a bullet
Step 3 :: Search for the new bullet addition total
Step 4 :: If you get more than one address(es), repeat steps 2 and 3
Step 5 :: Double click the address and lock it, remember, you can modify the values so that it'll be 130 again
Step 6 :: Lock the address and there you go, you'll have unlimited ammo
Note : Insted of shooting 1 bullet if you shoot more bullet it is faster to rinse.
I only tried it on the AUG. Tell me if any other gun works.