At first I was hesitant to go with plastic over steel, but after getting a few of these MTM cans in rotation, I recognize that concern as irrational. These are well built, and perfectly adequate for the needs of 99% of recreational shooters such as myself. If you planning to toss these cans out of low-flying helicopters, or maybe come under light mortar fire, I would recommend steel cans. If such scenarios seem unlikely, these plastic cans will probably exceed your basic needs.
Effective product. Durable, cost effective ($9.99), and reliable. Houses about 1,000 rounds of loose .223 ammo.
Durability is relative. I utilize these cans for storage purposes, and I've not traveled with a full can (yet). I've handled full cans by the handle and both the handle and lid closing clasp have maintained without an issue. I've not put a high level of stress on the cans (yet).
Grooves along the roof and base of the can supports stacking to a degree. 2 holes allows for locking the lid.
On a personal level, I've found success with MTM brand cases. I am happy with their products, both price and quality. The benefit of consistency allows for better storage and allows me to quickly determine a ball park figure on ammo count.
Note, I affix my own labels. Product does include labels (different from ones in my pictures). I also add my own silica gel packs, which are not included with this product.
TIP: you can hold more ammo if you dump your bulk rounds into the cans instead of keeping the paper boxes. I can get about 400 rounds of 5.56/223 into one of these. Have not tried 9mm yet.
Although the intended battery would not fit it still makes a fine dry storage box and I can get some use out of it. The orange model that is sized perfectly for the 12 AH battery has sadly been discontinued.