I don't reload so I don't have the problem, but from my experiences in the Corps I would say be wary of putting anything of technical spec. Performance that can corrode, oxidize, or tarnish in sealed containers in luring plastic bags. Sealed containers could lead to moisture even though minimal when container internal temperature is different that external. That can happen when say the internal temperature is set by cool night or evening temperatures and then meets warmer temperatures of afternoon. Remember the metallic items will retain a set temperature longer tha. The air around them. That can cause condensation. Changes in humidity add to the problems.

In Nam we dealt with a very corrosive environment in the norther section (I Corps). Cool nights compared to hot days. We stored things so Air would circulate. Moving air drys out moisture.

A locker that has desiccant in it is a good solution. Get some old metal lockers with ventilation vents and add shelves. Buy some 50 pound bags of rice and trays. Add 2 to 3 trays of rice on shelves in the lockers. Rice is a great desiccant and affordable in large quantities, which you can get from restaurant food suppliers.

Get a humidity gauge and put it in one of the lockers to track shifting levels. If the levels start to increase watch them and plan to change the rice.

Rice is also a great way to dry out wet electronics. My wife dropped her mobile phone in the kitchen sink full of water. She pulled it out quickly and dried it. It worked for a few minutes then dried. I buttied it in rice with the charger turned on. Between the moisture absorbing rice and the heat of the charging the phone dried out in about ten hours. It worked fine for years until she upgraded.

Another solution is to thermostatically control the temperature within the lockers by using electric hearters. Warm air is not going to be a problem until it is mixed with cold air. Combine the means and you are going to be very pleased.