ents.FindInSphere() returns a table of found entities.
You need to use it like this:
for k, v in pairs(ents.FindInSphere(position, radius)) do
if (v:GetClass() == "item_ammo_357") then
-- do whatever you want here
‘position’ and ‘radius’ are things you’ll have to set, please don’t just copy and paste the code into a file and tell me it doesn’t work.