Nanuk
IP67-rated waterproof long case with custom AR-15 foam, TSA-locking PowerClaw latches, and a tough NK-7 resin shell.
The Nanuk 990 AR is the case to recommend when someone asks for a waterproof box built around an AR-15 rather than a generic foam blank. It ships with hard foam pre-cut for a 36-inch AR-15, eight magazines, a pistol, and four handgun mags, so there is no Pick-N-Pluck cubing to do. The NK-7 resin shell carries an IPX7 waterproof rating, meaning full submersion to one meter for 30 minutes, plus IP6X dust certification.
Two of the four PowerClaw latches integrate TSA-accepted key locks, which clears the case for checked airline travel without a separate padlock. Polyurethane wheels and two spring-loaded handles make the 18-pound empty weight manageable. The automatic pressure-release valve equalizes after altitude changes, and Nanuk backs the case with a lifetime warranty. At $460 it sits at the top of the price range, but the AR-specific foam and submersion rating justify it for a dedicated carbine.
Add the Nanuk 990 AR Case to your build and see how it enhances your platform.