All ammo made by the major manufacturers, as members of SAAMI, conforms to SAAMI specs for that round.
I can assure you, NONE of them sell down loaded ammo to Walmart or anybody else. They have the same SKU and product number as those at Jim Bob's concrete, live bait and guns sells.
Ole Jim Bob @ the gun show may tell you that..but he is wrong !
Walmart pays no freight on the ammo..it is all delivered to the closest Walmart distribution center and trucked by Walmart to their stores.
Ole Jim Bob pays freight on every box of ammo he buys from a distributor unless he buys by the pallet load....add in his profit and it is going to sell for more than Walmart.
While it is important to support your local gun store and gun shows, in today's economy, price sells....it is the consumers choice.
Paying freight on a case of 45acp across the country UPS could cost a dealer $ 30 or more. That adds $ 1.50 more per box before he makes a dime on selling the ammo.
All factory ammo, for liability reasons, must meet the minimum velocity standards published for that round.