For the trust I will be naming my wife and myself as co-trustees so that she would be able to use the items without me present. I intend to name future children as successors for the items. In the even of our death I understand that our children would become owners of the items without need of paying a separate transfer tax correct? If our children are only successors, do they become authorized users after our death? I guess the real question is I am a little blurry on the difference between authorized user or co-trustee as I have heard it referred to versus successor?
You really can't set up a trust to name only people who do not yet exist as the only beneficiaries. You will need to address this.
If your children are named as beneficiaries, they can either have the trust sell the NFA items and distribute the proceeds or the NFA items will transfer to them individually on a Form 5, tax free. You might want to print a copy of BATFE Form 5 to see what would be involved in that transfer. I think it would be very difficult to leave one NFA item to multiple people, but there might be some work-around for that which I am not aware of.
I believe that in NFA trusts the Trustees are generally the authorized users. (I have a conceptual beef about this because Trustees are typically not permitted under the law to "use" assets that depreciate and wear out from use - that really makes them beneficiaries, which if BATFE ever catches on, would void the NFA Trust - they can't be that stupid, just willing to turn a blind eye to this for now