DIY gun safe?

[CapnMac]

Fire protection = no
Break in/theft resistance = yes
Esthetic = no, just needs to be hidden
Water resistance = no
Humidity/temp control = yes

Given that program, a spitball:
Choose an under-used closet of a suitable dimension. Clear all the stuff out of the closet. Measure and mark out the stud locations on the back wall.
Given that you want a horizontal orientation, while in from of the wall, mark out the highest, vertically, you want to reach up to stow a rifle. Similarly, mark out the lowest elevation while standing.
That space below to the floor can be used to advantage, with shelves for ammo boxes.
So, we can picture a box, with legs and/or sides, and shelves below.
Because of your preferred orientation, this box does not need to be deep, which can be used to advantage. If with a wrinkle.
This box will want to be about 54" wide. The closet is probably not ±12 + 26" deep, so that suggest that you need three doors, with two of those hinged together. How to latch that properly will take some separate brainstorming.

Oh, for a cheap way to line the inside of metal cabinets, one of my bros swears by the playroom floor mats; they come in big bundles at the box store, and the edges mesh together, and are easy to cut around brackets and the like.

 

[JTHunter]

HammsBeer - have you considered a used safe? If you live in or near a fair sized city (70,000 +), there is likely a business that refurbishes old safes. These are not likely to be an actual gun safe so you will have to build up the interior.
The biggest problem will be getting a safe like this into your house as these can be quite large and weigh over 1,000 lbs.

 

[HammsBeer]

I keep leaning more towards stealth vs brute strength. An unlined RSC hidden behind a wall with a welded grid of rebar around it to provide some added deterrent. Thieves would have to find the safe first, then destroy the wall to make enough room to cut the rebar, and cut enough of that to cut an access hole in the safe. And finally a home security system as well.

 

[DeepSouth]

I want to hear the "doesn't take much to to get through 1/4" steel" methods that don't ruin everything inside the box or safe. I can do it very quickly with the right equipment but everything inside will be junk when I'm done.

I have two ways myself
Cordless grinder and a couple cutoff wheels. Also a Milwaukee metal cutting circular saw, I have the 120v but they make a cordless one now.

Everything inside will be dirty but otherwise unharmed.

 

[doubleh]

Slow and noisy on steel a quarter of an inch thick. Not something a thief likes.

 

[FAS1]

Seems like some want to point out the extremes when that really isn't a reality for the most part. Common burglars and thieves are usually looking for the quick and easy score. Now if it's known that you have lots of valuables and are at risk of a planned attack then things could be different. That's not 99% of the incidents.

Thick steel, a quality UL rated mechanical lock, a well supported and solid locking mechanism, and if hidden is a plus as well. This will deter almost all.

 

[DeepSouth]

Slow and noisy on steel a quarter of an inch thick. Not something a thief likes.

True, but the fact is they’ll get trough pretty easy and not that slow, especially the metal circle saws. Those things are impressively fast on steel even over a 1/4”, it is noisy as heck though.

A simple locked metal box like a jobox will definitely deter the overwhelming majority of criminals, but let’s not pretend it would be nearly as secure as a real safe.

It looks to me like the biggest issue with a DIY gun safe would be securing the hinges and the edges of the door. Obviously it can be done, that’s just the two major hurdles that have to be overcome. Would be interesting to see what innovative people could come up with.

 

[doubleh]

I don't have any experience with the metal circular saws as they hadn't arrived on the market when I retired. I have a compound miter metal saw now that looks just like the wood working ones and it does a good job. I expect the hand held ones would too depending on the skill of the operator. I once thought about building a big gunsafe from 1/4" plate and having a good friend that owns a machine and fab shop with a shear and brake that is capable of handling 1/4" I could have made one just as nice as what you can buy. After adding up material costs and weight I went with a commercial safe. Sometimes just because you have the ability and means to make something it isn't really worth the effort. I made the base with drawers for my Jet milling machine back in the '70's. Why? There wasn't anything available that I couldn't make better and stronger. I just cleaned out all the drawers, rearranged (straightened up where I could find stuff, really) and oiled the slides last week. I have never had to re-level the machine in all these years so I guess I got it right.

If I had a safe made from 1/4" plate where I could get to it and not worry about setting something on fire I could easily open it with a cutting torch in not a long time and not damage or even get the contents dirty but we have been discussing protecting the contents from a quick theft and not not how to open a safe with out damage.