"Simple" SBR lower question (I think)

[Hmac]

There is no requirement to be able to return it to the configuration on the form.

Agreed. The whole NFA thing is way easy to overthink.

[prepare]

Some great replies! I really don't want to wait 6-10 months for approval of a Form 4 at my age (69). And, any and all firearms that I either own now or accumulate in the future I will keep until I die, and then my heirs can decide what to do with them. So resell value of the Form 1 lower is not an issue for me. I just want to have a legal sbr.

You still haven’t learned patience? Good grief...
Just kidding🙃

[lonestardiver]

There is no requirement to be able to return it to the configuration on the form.

Look on the form 1 under change of description. If you sell or trade or no longer have the original upper and you are using one of a different caliber or length you are making a permanent change. If you keep the original and swap out uppers as desired but have the ability to revert back to the “dimensions” as noted on the form 1 then everything is OK. I believe the ATF wants to know of “permanent” changes to a registered NFA firearm.

Item 4 is the description with parts a-i. Those include caliber, barrel length, etc.

[BigWaylon]

Look on the form 1 under change of description. If you sell or trade or no longer have the original upper and you are using one of a different caliber or length you are making a permanent change. If you keep the original and swap out uppers as desired but have the ability to revert back to the “dimensions” as noted on the form 1 then everything is OK. I believe the ATF wants to know of “permanent” changes to a registered NFA firearm.

Item 4 is the description with parts a-i. Those include caliber, barrel length, etc.

There’s no such thing as a permanent change on a modular platform.

They want to keep the registry accurate, but there’s no regulation that requires the end users to provide all those updates.

And I’ve seen multiple examiners ask people to stop sending in length/caliber change letters for ARs.

ETA: realize...
1. The forms are not the law; with a regulation to back it, there can be no enforcement
2. Recommend/want/suggest aren’t the same as require

[jackblack73]

Look on the form 1 under change of description. If you sell or trade or no longer have the original upper and you are using one of a different caliber or length you are making a permanent change. If you keep the original and swap out uppers as desired but have the ability to revert back to the “dimensions” as noted on the form 1 then everything is OK. I believe the ATF wants to know of “permanent” changes to a registered NFA firearm.

Item 4 is the description with parts a-i. Those include caliber, barrel length, etc.

There’s nothing permanent about it. If you can change uppers by simply pushing two pins, that’s about as far from permanent as you can get.