Sorry if this question had been asked before but will it cause any problem if I change the barrel length shorter from what I have in my FORM 1?

Send them a letter, letting them know if you are swapping or just adding a new barrel, and they will "update their files" and send you a thankful reply.

That way, if you're ever hassled, really hassled, and the LEO, etc., that is doing the hassling looks at your paperwork, notes the discrepancy and measures your barrel, you can calmly produce copies of your correspondence with the BATFE.

better to be safe.

Quoted: Send them a letter, letting them know if you are swapping or just adding a new barrel, and they will "update their files" and send you a thankful reply. That way, if you're ever hassled, really hassled, and the LEO, etc., that is doing the hassling looks at your paperwork, notes the discrepancy and measures your barrel, you can calmly produce copies of your correspondence with the BATFE. better to be safe.

That is if you choose to let them look at confidential tax information!

Quoted: Sorry if this question had been asked before but will it cause any problem if I change the barrel length shorter from what I have in my FORM 1?

if it is not a permanent change .. then just swap uppers .. you are golden.

if you are getting rid of the previous upper .. the ATF requests you let them know of changes but nothing is required by law.

What form would you need to fill out if selling a 10.5" upper indicated on the Form 1 and changing to a 7.5" upper permanantly? Or do I just "write them a letter"?

I have been down this road once before, 1st off the easyest thing to do is jsut keep the 10 in upper and buy a 7in. If you cant do this i.e. to many extra lowers, lack of funds for the new upper, you SHOULD send a letter to the NFA branch stating that you have removed the 10 in and that you NO LONG HAVE IT( import to have in there what happen to it, i.e. "i sold it") tell them the new barrel and Overall length as well as caliber change if need be. Keep a copy of the letter, that is your protection if you ever have an issue. Dont be suprised if you dont hear from NFA after you mail the letter, they are still back logged to APRIL 2007 so it will propbelly be a 1 year before they even read it.

Again, keeping the 10 and just buy in another is a much easyer way of doing things, if you have any questions Call SueAnn the secratry at the NFA she handles these letters and can tell you exatly what to do.

Best of luck.

You can in the future register a SBR with multi barrel lengths put all the combos on the form. Technically you can change uppers without a problem because the receiver is what is registered. I have had machine guns that the barrels had been changed to different lengths and the NFA just says all the have to do is Update the computer.