have to agree with some of the others here, my bow, probably not as I need it and it's my only one, also with different draw lengths etc...
a gun, even this is an iffy option, it would have to be a special friend/relative in a pinch who need to borrow one.
I remember years ago my dad borrowed our cousins rifle for a hunt all 3 of us were going on, at the time, he only owned 1 western rifle, which he bought for this trip, a .270, he borrowed a 30-06. Simply couldn't afford to buy 2 brand new rifles/scopes etc...for this trip.
For the most part I think there would be little reason to loan out a gun.