Response from Turnbull Mfg:
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Sunlight harms everything over time. It will not fade it any faster than anything else in my opinion.
Todd Burkett
Shop Supervisor
Turnbull Manufacturing Co., Inc.
585-657-6338
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I'm slightly puzzled in the sense that the answer can be interpreted as "it won't fade any faster than any other type finish", or, "sunlight won't fade it any quicker than other (unnamed) threats"
Either way, the answer seems to be that (long?) exposure to sun will eventually fade the finish. Is that months, years, decades, or longer? Dunno. I probably wouldn't hang a CC'ed gun on the wall in a sunny location. Other than that, normal use and storage should be safe. (I guess...
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