Ok, so I have been working on this rifle design for a couple of years now.  I have a semi-functional 3d printed prototype and will be applying for provisional patents in the near future.  Does anybody here know if there is any kind of “provisional” manufacturing license through the ATF so that I can make prototypes for further R&D?  I need to make a few and test them out before deciding if it is worth persueing manufacturing and seling them.  I dont have a mill or lathe yet or a place to put them, just trying to fugure out the legal side of things.  I am well versed in MG, barrel length, pistol, AOW type legal stuff.  It will be a bolt action rifle.  Thanks for any help!

Does an individual need a license to make a firearm for personal use?

No, a license is not required to make a firearm solely for personal use. However, a license is required to manufacture firearms for sale or distribution...

https://www.atf.gov/firearms/qa/does-individual-need-license-make-firearm-personal-use

At what point are you going from "personal" to "sale or distribution" will be a determining factor in your case

Its the distribution part thatll be relevent once I have made a few.  My thought process was to give a few out to friends and have them be beta testers and get their feedback.  Guess I will have do do the ffl and serial number them at that point.  
Thank you.

You can gift or loan rifles. I would think as long as you arent being compensated for the rifle, and they arent selling it, you are not in the business of firearms distribution. Especially if the firearm will be returned after testing.

Hmm.  Theres a thought.  There will be a paper trail of test and eval information that would show the purpose of loaning them out.

Get an 07 ffl. You will be in the "business" of manufacturing.  All of your costs of manufacturing and testing will be business expenses.  You will be able to make purchases at discounted cost as well. Run it like a business and take advantage of tax write offs as well.