Every gun we put into evidence that is not held for a case or returned to the owner is destroyed. One of our evidence techs, the wife of a good friend, told me to never ask what they destroy because it would make me cry.
Our former deputy chief (He is a top notch guy) told me that removing firearms from evidence was one of the more common ways officers become corrupt. Would I take drugs or money from evidence? Of course not. How about a WWII Garand, or Civil war Springfield? He was absolutely correct. That would be my slippery slope.
I choose to be ignorant in that area. I don't even want to be tempted by some rare historical piece that is about to be chopped.
More on topic. We did a "buy back" several years ago and took in way more than expected (and budgeted for). I believe every last gun was chopped. What a waste...
I am commonly asked at work by older people what to do with a deceased relatives gun. The person that brings it in is usually just trying to get rid of it in a safe manner. I encourage them, within my legal bounds, to take it to a reputable gun store and sell it as we will just destroy it. Most of them don't realize we are going to take their husbands WWII 1911 and chop it up.