I have had that experience, and this is what transpired. A local deputy sheriff called me one morning, and asked if I had a gun powerful enough to stop a really LARGE cat that had escaped from it's wild animal owner. He did not know HOW large, or what type of cat, just that it was loose, could be dangerous to the community, and MAY need to be downed quickly. As you might remember, Ohio recently has a LOT of wild AFRICAN animals released by a nut case owner south of Columbus, so the presence of other lions, tigers, and bears, oh MY, was very possible where we reside. I pondered it, and said, yes, he could borrow my .300 Win Mag, which I had several types of ammo for, including some with military AP bullets. The deputy is a 3 or 4 time graduate of Gunsite, and came over and sighted my rifle in for himself, and went out with my rifle. The cat was later captured by the owner, and was determined to be some intermediate (bobcat sized) exotic, and did not become a threat. I would not have handed my rifle to just anyone, and probably would have ridden along and been the shooter if it was not someone I knew to be competent. Many of our county's deputies are tactically trained, or on the team, and supervisors have access or carry gov't loaned M14's in the squad cars. I agree with the deputizing thing, should LE's need your gun AND "expertise" in use with it. If they can't handle that, then they should make do. Looking back to the N Hollywood shootout, the LAPD "confiscated" guns from a local gunshop (BumbleBee Sales) to stop the bank robbers, and the gunshop got treated rather badly by LAPD before that, and ultimately went out of business due to harassment and overregulation over the years. That was their "thank you" for loaning the guns to the police. Read about it here:
http://www.thefreelibrary.com/NOHO+SHOOTOUT+GUN+SHOP+GOES+BANKRUPT.-a083012785