These ($40 on sale @ Menards) are rated for 450# bottom shelf, 350# each for the next 2 shelves, and 300# for the top which must be a consideration for tipping chances since all the shelves/supports are the same. I slipped a strip of 1/2" treated plywood under the middle of the bottom shelf that was loaded with 4K rounds of .223 but the others I'll just watch for sagging. When a decision is made on relocating the ammo shed these shelves will have to be moved but in the short term this has made a big difference in accessibility.