From what i've researched, the #1 reason to have a gun trust -- i.e. one that is separate from yout regular financial trust -- is owning NFA restricted items.
If you have a suppressor and a machine gun, you can't let anyone else use it unless they also send the ATF $200 and the proper forms -- then wait forever. And as we know, machine guns can't be transferred (with some exceptions) -- so, no lending or borrowing either.
By putting your NFA items in a trust and naming other family members and friends as co-trustees or beneficiaries, they all have legal access to everything contained in the trust. If Uncle Joy wanted to borrow that machine gun, he's legally allowed since the actual owner is the trust of which he is a part.
If the purpose of the trust it to bequeath it, then the trust also makes that easier. if the heir is a beneficiary of the trust, there's no transfer needed and no ATF applications or taxes.
For regular firearms, you can include those in your personal trust that you might have your investments, bank accounts and home part of. Without any trust in place, the inheritance process will be a little more effort -- permits, NICS background check, HI registration for the heir -- but it saves the hassle of setting up and managing a trust. It can also save money if you feel the need to hire an estate planner/attorney.
Gun trusts have become popular for shooters allowed to own NfA items where they live. Lots of benefits and very little downside.
Trusts survive the trustees, therefore there's no transfer or inheritance. A name is merely removed from the trust's list of trustees.
