I did considerable research on local fire codes a couple years ago, and they vary considerably. Many are in the 200-pound range.
Yes, they do vary and mucho. The 200 pound limit you found probably comes from the NFPA (National Fire Protection Association) which seems to be the gold standard on fire protection. Our state inspectors and fed inspectors (at least in part) require compliance for commercial operations. The part on smokeless powder is reprinted in the SAMMI pamphlet that I linked to in a post back a few.
For property insurance it all depends on what the insurance contract says of course. If you have an agent maybe he could help decipher your policy. But I doubt he even thought about the matter before.
That's all I know, never had enough powder in the basemen to be anyway near anyone's limit.
