Can the registered owner of a short-barreled-rifle reconfigure it freely?

Question

I am considering building a short-barreled-rifle from a Ruger Charger and registering it on an ATF Form 1. Part of the Form 1 has a box for barrel length and overall length. Since it is a 10/22 action, I would like to purchase a variety of stocks and barrels. That way, 1 receiver could serve a variety of roles depending on which parts I use. I could own 1 rifle and 5 sets of parts instead of 5 separate rifles.

After registering it, will I be able to (legally) change the barrel length at will? What about the overall length?

Please answer only if you are knowledgeable about NFA firearms and the law. I really need verifiable sources, whether it is a section of law or a link to an ATF letter.

Answer 1

As long as the shortest configuration is registered you can do what you want with the receiver as far as adding to the barrel or stock dimensions

SBR laws are about the shortness of the rifle more than the length

Your absolute best option and the best advice anyone can give you is to write a letter to the ATF and save the letter they send you in response to this question

Answer 2

When I researched making my PLR into an SBR, I was told that once you do it, it MUST stay in an SBR configuration. If my memory serves correct, the serial numbers are registered as an SBR with the government, and an added number is issued to the firearm as an SBR indentification.