MTM Products J20M41: The MTM Case-Gard J-Series of Rifle ammo boxes are a favorite of rifle shooters around the world. The J-Series is designed with a slip over the top for excellent ammo protection and ease of transportation. The cartridges are placed in the box in the up position, and foam can be purchased separately and inserted into the lid if more bullet protection is required. These cases are made of a polypropylene material that will not warp, crack, chip, or peel.