Primer Storage
Due to their explosive nature only an absolute minimum should be kept in storage. The National Fire Protection Association' NFPA 495 says that not more than 10,000 primers should be stored in a private residence. This recommendation is law in most communities. Even a deeply involved reloader should have no reason to store more than 1,000 of each of large rifle, large rifle magnum, small rifle, large pistol, large pistol magnum, small pistol, small pistol magnum, and shotshell primers. That's 8,000 primers. With care in replacing exhausted supplies, it is not difficult to adhere to the 10,000 primer limit. Many, if not most reloaders will be able to get along nicely with far fewer primers kept on hand.
Always store primers in a remote area away from any possible source of ignition including bullet impact. Be sure no heat, spark, electrical percussion, or any other form of abuse can occur in the storage area.
Keep primers stored away from oxidizing agents, flammable liquids, and flammable solids (including handloading powders).
A storage cabinet is strongly recommended. A cabinet should be solidly constructed of 1" thick lumber to delay the transfer of heat to the contents in the event of a fire. or other mishap. Make sure the storage cabinet is remotely located with respect to trash, combustible materials, sources of heat (including sun rays), open flames, electrical equipment, hot water heaters. mechanical equipment, furnaces. solvents, flammable gasses, and so on. To avoid the potential of an unexpected or unusual accident, do not store anything else in the primer cabinet.
Naturally never smoke around primers. No smoking signs in the storage area and at the loading bench are suggested.
A bulletin is available from SAAMI entitled "Sporting Ammunition Primers: Properties, Handling, and Storage For Handloading".
Powder Storage
Generally, propellants used in sporting arms cartridges will not explode or detonate when ignited. Burning smokeless propellants do not generate the shock waves produced by an explosive. Unlike ignited smokeless propellants, the results of an explosive defies the adequate venting of shock waves even when it occurs in the open.
Ignited stored powder can raise pressure within the storage area, thus there are specific requirements for keeping powder on hand. The first of these is never to transfer any propellant from its original container, which is designed to burst or partially open at a very low pressure. Some containers will simply have their cap pushed off if the contents are ignited. This will then allow for all the gasses to be vented from the container. (keeping powder in the original container is also essential for the proper identification of the propellant).
Ignited powder will continue to burn until it is completely consumed. Therefore, stored propellants should be kept away from any source of ignition.It is imperative that the storage container have one or more weak walls. These will open out at very low pressure to vent gasses before they can cause damage in case of unintended ignition. Without this built-in protection, a strong enclosure could burst with considerable force possibly causing property damage or bodily injury.
Other storage cabinet recommendations include construction with heat resistant fire insulating materials. The cabinet should be sufficiently large to adequately vent gasses if a container were inadvertently ignited.
Storage cabinets are often made of 1" thick wood with one or more walls designed to open outward, or blow free at very low pressure. They should be many times larger than necessary to store the minimum quantities of powder.
Do not store propellants in the same area with solvents, flammable gasses, primers, or any highly combustible materials. Smoking should never be allowed in the storage areas or while handling and using powder.
Many municipalities use the National Fire Protection Agency's publication NFPA 495 as law. It, in part, states that smokeless powders intended for individual use shall not exceed 20 pounds unless stored in a wooden cabinet or box with the walls of at least 1" nominal thickness. Even then the storage quantity shall never exceed 50 pounds.
Spilled powder should never be picked up with a vacuum cleaner. Use only a brush and pan and dispose of the powder in a safe manner.
The nitroglycerin of double base powder can be absorbed through the skin, by breathing vapors, or by ingesting. Symptoms can include headaches. The following precautions must be observed when handling double base powders. In case of accidental ingestion induce vomiting and immediately call a physician. Prevent contact with food, chewing material and smoking material. Ensure adequate ventilation during handling and reloading procedures. Wash hands thoroughly after handling. Follow specific manufacturers precautions.
A bulletin is available from SAAMI entitled "Sporting Ammunition Primers: Properties, Handling, and Storage For Handloading". Every reloader should acquire a copy from: