I am guessing that you have a lot of old powder and need to move it out of the tin kegs. You might also ask around some of the gun clubs in your area and see if anyone is finishing off any powders in plastic kegs. Otherwise, I would recommend going to the dollar store and getting the largest air tight plastic containers you can find, the only problem is that they will most likely not be opaque. Since powder comes in an opaque container I am guessing it is to protect it from UV so if you move your powder to a translucent container you will need to keep it from being exposed to the sun light. The only issue I know for sure if concerning containers for smokeless is that they are suppose to have a low bursting pressure in case of a fire so the don't detonate only burn.