I am still learning about primers, but over the years, I have learned about smart and dumb things to do with explosives. Alaska, somewhere back in the 90s.
What about long-term storage? Time isn't much of a factor in primer performance, but temperature cycling is. Going up and down in temp induces condensation.
Yes, there are inherent dangers of this, frankly, in ANY storage of explosive bits and pieces. Primers are primary explosives, and just putting too many of them together in one place makes them "a bomb" whether they are contained or not. The metal box storage would be a concussion explosion, and the shrapnel would not be as much as you think, but it certainly is a risk. Anyone that reloads in any bulk has all kinds of stuff that will go "boom". Some do it in shops separate from the home, and some do it in a house with precautions, such as a magazine built into the structure.
The hazard from the metal box is more about it creating an isothermal (uniform temperature) environment inside during a fire as it is about fragmentation. I would not want to be the fireman working near a hot metal box full of primers. Yes, the house could catch fire That's a risk I live with. I, for one, drive too fast to lose sleep over it. But if I plan on storing something long-term, I don't know any other options.
Stored in their original containers, packed in a can, I think the risk of them "cooking off" on their own is pretty slim. But NO, an ammo box WILL NOT "contain" them if they did cook off. But I wouldn't want something that strong anyway because it would only increase the explosive release if it does go up (why I don't store them in a gun safe, among other reasons). For long-term storage, the sides of a GI box would blow out plenty fast enough to prevent excessive pressure build up and it protects your primers from humidity like nothing else if you want to store for years, not months. I know folks who have taken a 1-inch hole saw (fine tooth) and thinned a place from the inside of the lid to direct the force of the blowout, though it brings to mind "The Crimson Permanent Assurance".Some of the primers that have lived around the Range over the years were stored for a very long time and were still good when used. Had they been in plastic, even with desiccant, they could have ended up duds. (Click to enlarge and look at the price on this box. Do you want to guess how old it is?) This box was stored in an ammo can, not a plastic can, and it is as good as new. The problem with plastic containers may be the vapor permeability of the material itself. Plastic gas cans/vehicle fuel tanks were only possible after the development of a flourination process used to create an impermeable layer in the plastic after the part is formed. But I know many will disagree with me and there's lots of discussion pro and con in the forums on storage. If you're worried about a fire, store your primers in a plastic ammo box, like you see pictured, still in their original packaging. The original packaging is designed to be non-static so you shouldn't have a problem with the plastic box. If a fire causes the box to melt and if the primers cook-off, when the first package pops, it will help scatter the rest of them. A pack of 50-100 primers would make a decent bang, but the flying bits are small and low-powered. Plastic is acceptable for the short term, but in my humble opinion, if you want primers that will be useful 10 years from now, plastic will not cut it unless you own a desiccant factory. (Note: the desiccant is going to do less than you expect if the individual boxes aren't sealed. The primers are assembled in 30% humidity, and anything much less causes the cake (the pressed mixture) to crumble.)
My primers are stored in their original boxes, with several desiccant pouches and a humidity indicator. I have the primers I will use soon in plastic containers with desiccant, but I also have a couple ammo cans packed for long-term need, one for small rifle & pistol primers and the other for large & magnum primers. They're kept in a cool, dry environment until I might need them someday when times get tough, and I only keep the can in use long enough to select what I'm going to use and occasionally replace the desiccant.I've never heard of primers in their box, stored in an ammo can, going off on their own. In a reloader, yes, but the can no. Has anyone else? If my house burns, I'm in a lot more danger from the ammo than from two or three cans of primers stored in a carefully constructed magazine.
I don't keep my powder in a sealed or airtight container, but I feel safe putting some of the primers in an ammo can. I don't want anything to crush them and make them pop, and I don't want flame to get to them and make them pop. I also don't want humid air attacking them.If you are going to store primers in some cabinet in your house there ARE some basic rules you wish to follow. Don't use your primer cabinet to store -
You can also identify your storage area with NFPA markings to aid firefighters responding to an emergency at their home -
The NFPA 704 marking system consists of a diamond-shaped placard divided into four sections: a white section on the bottom for special hazards, a blue section on the left for health hazards, a red section at the top for fire hazards, and a yellow section on the right for reactivity hazards. Each color box contains a number from 0 to 4, specifying the corresponding hazard level for the material contained in the container or area.
So for powder, primers, and most reloading materials, the white square at the bottom would be blank, the blue square on the left would contain a "0" for no specific health hazard, the red square at the top would contain a "3" for moderate fire hazard, and the yellow square to the right would contain a "3" or a "4" for high reactivity hazard, depending on what you're storing. Google NFPA Marking System for more info. Naturally, never smoke around primers. If the area where you reload is frequented by guests or household members who may not be familiar with the process, No-Smoking signs in the storage area and at the loading bench aren't a bad idea.
Again, these are just some basics of what I do. Others will have better info, and others will disagree. But on the issue of the ammo argument, you might wish to reference
Boring, yes, it's the federal requirements for packaging Primers, Cap Type, UN0044 (i.e., ALL small arms primers that we, the public, use). According to that reference, primers MUST be packaged in a certain way, but choices are allowed within specific parameters. For example, it references inner packing, which consists of "Trays, fitted with dividing partitions" as one option (this is what some of you are used to seeing). The reg above requires that if the primers are housed in trays, as mentioned in (1), then intermediate packagings are required. Follow the link above to page 11 of the PDF, look at the "Intermediate packagings" column for packing instruction 133, and see that we can store the tray of primers in a receptacle made of (our choice) fiberboard, wood, plastic, or METAL.
Finally, the regulation gives folks that fall under their guidelines a choice of outer packaging, noted in the 3rd column of page 11 of said PDF-- steel box, aluminum box, wooden box, plywood box, and plastic box, among others. I know these regs don't apply to us, the individuals, but it's nice to read what they consider safe choices for various purposes. Use common sense, check out local laws if you are so inclined, and follow some standard safety practices of not just HOW you store them but WHERE. Frankly, given where I live and what's on the radar at this time of year, I worry more about Mother Nature than Mr. Primer. Boring, yes, it's the federal requirements for packaging Primers, Cap Type, UN0044 (i.e., ALL small arms primers that we, the public, use). According to that reference, primers MUST be packaged in a certain way, but choices are allowed within certain parameters.
For example:
It references inner packing consisting of "Trays, fitted with dividing partitions" as one option, (this is what some of you are used to seeing). The reg above requires that if the primers are housed in trays, as mentioned in (1), then intermediate packagings are required. Follow the link above to page 11 of the PDF, look at the "Intermediate packagings" column for packing instruction 133, and see that we can store the tray of primers in a receptacle made of (our choice) fiberboard, wood, plastic, or METAL.
Finally, the regulation gives folks that fall under their guidelines a choice of outer packaging, noted in the 3rd column of the same page 11 of said PDF-- steel box, aluminum box, wooden box, plywood box, and plastic box, among others.
I know these regs don't apply to us the individual, but it's nice to read what they consider some safe choices for various purposes.
Use common sense, check out local laws if you are so inclined, and follow some standard safety practices regarding not just how but also where you store them.
For frankly, there are more things to worry about than your primers some mornings.