I recently decided to switch to a shotgun for my primary home defense piece. To that end, I picked up a Mossberg 500A Mariner in 12 gauge. Once the gun was proven at the range, I needed a way to secure it from curious kids.
I ordered a Loc-Box directly from Mossberg. It consists of two primary parts: the Loc-Box itself and a hook that goes into the muzzle of the gun.
Here's a pic of the main unit, with my shotgun in it:
The main reason for the hook is to stabilize the gun. The locking part of the unit is what secures it. Here's a pic of the muzzle:
Per the instructions, you are supposed to mount both parts to the wall by screwing them into a stud. Mossberg supplies three long wood screws for doing so. I did it slightly differently, attaching them to pieces of wood which are attached to the wall; one piece of wood was already in my closet, while the one for the muzzle hook is a scrap I attached to the sheetrock using Gorilla Glue and 8 drywall screws.
To use the Loc-Box, you unlock and open it. Then, slide the gun's muzzle up onto the hook, and then hang it on the hook through the open ejection port (the gun's action has to be open to put it in the Loc-Box). Then close and lock the unit. Here is a pic of the unit unlocked and open. You can see the hanging hook in the middle.
By hanging the gun on a hook through the open ejection port, there is no way to bring the gun into battery with the gun in the lock. Also, nothing goes inside the trigger guard. I specifically did not want a trigger lock because they can cause accidental discharges with loaded firearms.
As you may be able to tell, the hook that you hang the gun upon, and also the muzzle hook, are vinyl coated to protect your gun from scratches. The inside of the Loc-Box is padded, but the inside lip on the right is not. I covered the lip with electrical tape to prevent my shotgun from getting scratched.
The Loc-Box comes with two keys. I have one on a keychain on a hook hidden in the closet, with the other on the keychain I keep in my pocket. I can see fumbling for the keys in an emergency, especially in the dark, so I'll probably unlock the unit at night, then lock it in the morning. As shown in the picture, the Mossberg Mariner has the safety on, action open, one round of Remington OO buckshot on the carrier, and four in the magazine. A full reload rides in an Allen butt cuff.
Cost with shipping from Mossberg was around $40, which I consider reasonable. I do not believe that this will stop a determined thief. However, for those of you who need a device to secure a shotgun against curious children*, this is a good option. Aside from Mossberg's own shotguns, it will fit a Remington 870, and probably most other slide action gun, and many autos as well.
* I have two small children. I am firm believer in gun-proofing kids, rather than trying to child-proof guns. They know to not touch my guns without me there. But until they are older I wanted a second line of defense against curious hands.