You don't need a will according to federal law
Federal law verbiage does not specify "will" or "probate".
To echo JRW...
[the law regarding interstate FFL ownership transfer] "shall
not apply to ... the transfer, transportation, or delivery of a
firearm made to carry out a bequest of a firearm to, or an
acquisition by intestate succession of a firearm by, a person who
is permitted to acquire or possess a firearm under the laws of
the State of his residence..."
Read it yourself: http://codes.lp.find...ode/18/I/44/922
As long as you don't need them shipped, which is generally a can of worms between non licensed individuals even intrastate, I'd just go get them. If you're really concerned about it, y'all could do a little signed written statement listing guns/serials and have it notarized, but meh, lawyers aren't necessary for every damn little thing in life.
- OS