Hypothetically speaking

[rmabrey]

If one were to submit and get approval for a form 1 stating 300 blackout caliber with an 8" barrel, then later acquire a 11.5" 5.56 barrel, then forget they filed as a 300 blackout and sell that upper.......what steps if any would need to be taken?

Hypothetically of course

 

[dudley0]

Should keep the original upper... if only because it will be fun to shoot.

I think you can send in a change form to let them know, but I have not heard of anyone doing that.

 

[Bsj425]

If one were to submit and get approval for a form 1 stating 300 blackout caliber with an 8" barrel, then later acquire a 11.5" 5.56 barrel, then forget they filed as a 300 blackout and sell that upper.......what steps if any would need to be taken?

Hypothetically of course

Doesn't matter, once you have stamp in hand you can change length and caliber

 

[ROLEXrifleman]

Update ATF with change made if you know you will not have an upper in that configuration

 

[Slow Hand]

Doesn't matter, once you have stamp in hand you can change length and caliber

You can, but if it's a permanent change, ie selling the upper that was associated with the original F1, you are supposed to inform the atf. I did this with an F1 suppressor that ended up being considerable shorter than when I filed the F1. They sent me back a thank you letter a few months later indicating that the registry had been updated. Do you need to do it, realistically? Probably not, but if you want to follow the letter of the law; then yes.

 

[SteveM4A1]

You can, but if it's a permanent change, ie selling the upper that was associated with the original F1, you are supposed to inform the atf. I did this with an F1 suppressor that ended up being considerable shorter than when I filed the F1. They sent me back a thank you letter a few months later indicating that the registry had been updated. Do you need to do it, realistically? Probably not, but if you want to follow the letter of the law; then yes.

I would like to see a citation for this letter of the law that requires one to notify the ATF upon a permanent change to a SBR. They used to recommend that if you are making a permanent length or caliber change, then write them a letter notifying them as such. However, the links we used to use as citations for this answer are no longer available on the ATF website, so I wonder if they are trying to change things or just make it even harder for people to get answers to questions.

So, is it required to do anything? No, at least not in the past.
Should you send them a letter so they can update their registry? That is up to you.

 

[cop car]

I like these "Hypotheticals". Why would you even bother? Just do it right. I waited until mine was approved for a 6 inch .50 beo. Then I wrote them a letter informing them I wanted to modify my sbr and requested 35-40 calibers and barrel lengths be added. Kept the original envelope with all the dates on it and put it back away along with my paperwork. It's easy to get approval. Everyone should get all ar15 sbrs approved for all calibers. Preemptive for any potential law changes.

 

[mikefraz]

I like these "Hypotheticals". Why would you even bother? Just do it right. I waited until mine was approved for a 6 inch .50 beo. Then I wrote them a letter informing them I wanted to modify my sbr and requested 35-40 calibers and barrel lengths be added. Kept the original envelope with all the dates on it and put it back away along with my paperwork. It's easy to get approval. Everyone should get all ar15 sbrs approved for all calibers. Preemptive for any potential law changes.

I never thought about doing that. That's really smart.