To me, the best way to ship ammo is via UPS the cheapest way possible. And I’ve started using the ‘Limited Quantity’ label instead of the older ORM-D label.
FedEx declined to ship a brick of 22lr at their hub. Went to UPS hub and the woman there took my shipment and didn’t look at me like I was a drug dealer or something unlike the FedEx lady.
UPS Ground or Fedex Ground are your ONLY options, chose whichever is cheaper or more accessible for you. Most have "limited quantity" label attached. Do not go to UPS Store, Fedex Kinkos, ect, MUST go to a hub.