Scenerio - Im going on long vacation and dont want firearms in house, can a relative in MD store them ? Long guns, shotguns and ARs ?

What are the laws for ARs in MD for someone storing them. Locked in Pelican Cases

Doesn't sound feasible...

#1: Firearms crossing state lines to another person are supposed to be transferred through an FFL. Were your relatives in the same state as you, especially being in WV, I'd say "no problem", but....

#2: You would have to ensure the firearms were not on the banned list. If they were on the list, you could not transfer them here, even if through an FFL.

Hopefully, someone with more knowledge will post, but I don't think you can do it without doing an interstate transfer.

How long is the vacation?

Honestly i would just get a closet size storage unit for 50 bucks a month,  not necessary because i would be worried about compliance to a law that is not enforced, but because of convenience and less of a chance for something weird going down.