I lent a friend (Jim) my Mini 14 probably 7-8 years ago when his son had about out-grown his .22. Said son graduated to a .243 several years ago.
Jim is also a Scoutmaster, and a fair number of Boy Scouts (including his son) have gotten to shoot that Mini over the years.
Just got that Mini back a month or so ago.
Still looks great; now I have to go out and shoot it.
Lent another friend my 1911 so he could take his CHL range test. He shot it well, and it gave him the confidence to take the test. Then he went and bought a couple smaller guns for carry purposes. He has taken his wife to the range recently, but she is not at all happy with either his 642 or his LCP, so I may lend him a few others for her to try.
Another friend has been taking his wife shooting, and again, she does not like then guns he owns, so I offered to let him try a few of mine for her to try some weekend.
One final guy is a co-worker who is also a rangemaster at my local range. He expressed some interest in my recently-purchased Kimber Solo, and I offered to lend it to him some weekend. He has at different times borrowed my Kahr PM9, my Kahr CW380 and my 638.
Note that all of these people are long time friends and CHL holders, and 45-55 years old. I'm not the slightest bit concerned about their trustworthiness...if I were, I wouldn't make the offer.