MTM Ammo Box 7Rem -338WinMag 20rd Slip

• 20-round capacity: Keeps a practical field or range quantity of rifle cartridges together in one compact box, making load organization and transport simpler.
• Slip-top design: Gives fast access to cartridges when loading magazines or topping off a rifle, while still covering the rounds for storage between uses.
• Polypropylene construction: The rigid plastic body resists warping, cracking and chipping better than brittle storage boxes, so it stands up well to repeated use in the workshop, vehicle or hunting pack.
• Long-action magnum fit: Sized for cartridges in the 7mm Rem. Mag. to .338 Win. Mag. class, giving handloaders and hunters a dedicated box for longer rifle rounds that do not sit well in standard short-action cases.
• Made in USA: Domestic production and MTM’s long focus on shooting accessories make this cartridge box a straightforward, purpose-built storage option for rifle ammunition.

About the J-20 Series

MTM CASE-GARD J-20 series ammunition boxes are built as compact, caliber-specific storage for rifle shooters who want a simple way to protect and sort loaded rounds. Within MTM’s ammo box lineup, the J-20 format focuses on a 20-round capacity and a lightweight slip-top layout that suits hunting trips, range sessions and load development at the bench. Rather than using a one-size-fits-all approach, the series is offered in several internal sizes so different cartridge families sit more appropriately inside the box.

The series is known for its polypropylene construction, which keeps weight low while offering better resistance to cracking, chipping and dimensional change than more brittle plastics. That matters for shooters who store ammunition in changing temperatures or carry spare rounds in a pack, vehicle or shooting bag. The J-20 concept is straightforward: keep cartridges upright, keep labels and loads organized, and make it easy to grab a manageable quantity of ammunition without carrying a larger case than necessary. For reloaders, hunters and general rifle owners, the J-20 series fills the gap between loose cartridge storage and bulk ammo boxes.

About the MTM Ammo Box 7Rem -338WinMag 20rd Slip

The MTM Ammo Box 7Rem -338WinMag 20rd Slip is the long-cartridge version of the J-20 concept, intended for shooters using cartridges in the 7mm Rem. Mag. to .338 Win. Mag. class. Its main advantage is fit: longer rifle rounds need more internal length than standard .308- or .30-06-sized boxes, and this model provides that extra room while keeping the overall case compact enough for field carry. For hunters, that means spare ammunition stays together and protected in a pocket, pack or vehicle compartment instead of shifting loosely.

The slip-top lid favors quick access. It is a practical choice for range work, load testing and hunting use where cartridges need to be reached without dealing with a more complex latch system. The 20-round capacity is also well judged for magnum rifle ammunition: enough for a day’s shooting or a hunt, without adding the bulk of a larger storage box. Because the body is made from polypropylene, the box remains light at 70.00 g and is better suited to repeated opening, transport and general handling than thin disposable packaging.

Its 152.00 mm length and 76.00 mm height reflect its role as a dedicated cartridge box for longer rounds rather than a general-purpose container. In practical use, this makes it a sensible accessory for reloaders who separate loads by bullet type or charge, and for rifle shooters who want a durable, reusable way to store and carry ammunition.

About MTM

MTM Molded Products Company began in 1968 in Dayton, Ohio. The company remains family-run and manufactures its products in Dayton, with a strong focus on practical gear for shooting sports, hunting and outdoor use. MTM is especially well known for molded storage and transport products, including ammunition boxes, ammo cans, firearm cases and other shooting accessories designed around everyday field and range use.

Over time, MTM expanded beyond shooting equipment into products for archery, reloading, camping, hiking, fishing and overlanding, but organized ammunition storage remains one of its core categories. That background is directly relevant here: MTM’s cartridge boxes are built around simple molded designs, durable plastics and caliber-specific fit rather than unnecessary complexity, which is why they remain common on loading benches and in hunting kits.

Main Features

• Manufacturer: MTM
• Product type: Cartridge box
• Capacity: 20 rounds
• Cartridge fit: 7mm Rem. Mag. to .338 Win. Mag. class
• Material: Polypropylene
• Length: 152.00 mm
• Height: 76.00 mm
• Weight: 70.00 g
• Made in: USA
• Application: Ammunition

Warranty

MTM covers this cartridge box with a 2-year warranty. This stated warranty period suits a simple molded storage accessory intended for regular transport, bench use and field carry.