I have a chance to buy an NFA item from a business associate.
Can we just submit the form 4 or do we need to go through an sot?
I guess I would call it a personal transfer?

Thanks for the responses

In general, if you and the seller both live in the same state, you two can submit the form 4 yourselves. No need to go through a dealer. If the seller and buyer live in different states it will have to go through a dealer in the buyers state.
It’s likely some states will require the transaction to go through a dealer.