Loaning out a C&R rifle question

[mackbamf]

So I have a relative out of state who I may want to loan an old Mosin I have for an extended period of time, maybe 6 months to a year. If I ship it to him I would have to ship from FFL-FFL where he would have to do a background check to take possession. He is a truck driver and periodically comes thru Colorado. Since this is a C&R rifle can I just give him possession or since he would be crossing state lines with it would I need to do an FFL transfer to keep it legal? To clarify there is no issue with a background check for him, he already owns a firearm, I am just trying to find the cheapest and legal method to get it to him...