UPDATE: The process used by Trusts and Corporations to obtain Class III weapons is currently being reviewed by the ATF pursuant to an Executive Order. I will update as soon as I have more clear information on what effect this will have on Gun Trust usage and ownership of Class III weapons.
Why is it a hurry up and wait proposition? The ATF has to review the paperwork sent to them and this process can take anywhere from three months to over a year from what I have heard. There is no bright line rule for how long it will take or why and anyone who tells you that there is a way to speed up the process is simply wrong. However, it will slow down your process if you submit incorrect or incomplete forms, so be extra mindful of how you are filling out the paperwork and be sure to ask questions when you have them. Nothing is more frustrating than waiting a few months just to get your forms back for incorrect information.