These are the newer CASE-GARD ammo boxes. Made of virtually indestructible polypropylene that will not warp crack chip peel expand or contract MTM CASE-GARD rifle ammunition cases are still the first choice of rifle enthusiasts throughout the world. Mechanical hinge that is guaranted for 25 years. Snap-Lock latch protects contents from accidental spilling. Textured finish makes it easier to grip and harder to scracth. - In the late 1960's the original RS-S-50 was designed specifically for benchrest shooters. The CASE-GARD 50 which is available in eight sizes will hold .22 Hornet to 375 Remington Ultra Mag. with each cartridge resting in its own individual compartment. Each CASE-GARD 50 ammo box is supplied with a load label for recording load and sight data. All rounds listed as bullet up unless noted. See ammo box charts for more calibers.