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I am currently loading 44 special and 38 special with Alcan AL-5 and AL-8. These powders ended production around 1973 so I’m reloading with 40 year old powder and it works fine. i’m also using Hercules (now Alliant) Reloader 21 which is also about 40 years old. You are right about storing powders, keep then cool and dry.
You can use straight wheel weight but I use lyman #2 formula: 9 lbs. WW & 1lbs. 50/50 bar solder. Alox to lube and size bullets .002 over groove diameter

I want to thank one and all for responding to my questions about the stability of smokeless powder. Your responses are the sum of many years of experience and such knowledge is hard to come by (except perhaps on a forum like FR). The results are not as I expected, two of you had no problems at all and two had sporadic problems. This led me to conclude that there is a potential problem but it doesn't occur on a regular basis.

I did some background research on the manufacture of smokeless powder and other nitrated compounds (explosives, not propellants). The nitrification process is the same for all of them. Cellulose is treated with nitric acid which produces nitrocellulose and water as a byproduct. This produces a poor grade of end product and the yield is low because the presence of water stops the reaction. To address these problems a mixture of nitric and sulfuric acids are used instead of just nitric acid. The Sulfuric acid does not enter into the reaction as such but it is "hydrophylic" (water loving) and it removes the water byproduct of the nitrification reaction as fast as it forms, allowing the main reaction to go to completion.

At this point the acid soaked nitrocellulose is "washed" with cold running water to remove ALL traces of acid from the finished product. ANY REMAINING ACID WILL CAUSE THE PRODUCT TO BE UNSTABLE. This is true of a low explosive like nitrocellulose and also high explosives like nitroglycerin. It is possible to use this basic process to produce explosive compounds from glycerin, propyl-glycol, ethyl-glycol, ethanol, methanol, isopropanol, and mannitol (virtually any alcohol).

When working with the more complex nitrated compounds the "washing" process becomes more important as the complex molecules tend to decompose more rapidly. It is possible that spontaneous explosions may occur as rapid decomposition becomes a chain reaction. I found no references to this occurring with any nitrocellulose based powder. However, nitrocellulose does mix readily with any of the above mentioned alcohol based explosives and may be used to produce a "double based" powder. I believe that nitroglycerin is used in such powders and it does display such stability issues. I would recommend that users of double base powders refrain from storing large quantities of such for long periods of time. You are putting your faith in the manufacturer's quality control to a rather large degree.

Regards,
GtG