1031 exchange?

I'm a gun shop owner and I've got a guy bringing in 14 firearms, all mint condition and mostly C3 to C10. He is looking to put all 12 together and I will give him a trade in credit and he will apply for a 1031 exchange. Can this be done? He said it would be easier for him since he won't have to pay that large tax bill and it would be easier for me since I don't have to pay that larger bill either.