Guns:
Wood shrinks due to a loss of moisture content. This can occur from age, the atmosphere or both. Replace some moisture and the wood may well swell back up to its previous level. But some won't. And it is fairly unpredictable. "Quality" in wood is a variable term. Good stock wood is dried to a specific moisture content, but once the stock is made, it can swell or shrink depending on where the gun "lives." In Arizona, it will be one size. In Oregon, another.
I'd suggest your friend not be so manic about moisture in the safe. Just dry enough to prevent moisture condensation is dry enough.
Best, Kensal
