Can I have more than one SBR upper for the same registered lower? Or am I limited to one upper at any given time? My registration lists several calibers, so can I have all three uppers at the same time? I did a search and found no clear answer. Any help is appreciated.
Basically yes.
C4
I dont have the document in hand, but you can use multiple sbr uppers on a legally registered SBR lower. If your Form 4 as “multi” as the caliber, (lucky SOB) then you can use those calibers on your SBR.
I drafted a letter to the ATF and let them know I planned on using my SBRd lower in different configurations and mailed it in registered mail, but received no written confirmation from them about it though…
You can have as many uppers as you want as long as you have that registered lower.
Best rule of thumb I’ve heard is just don’t have any built lowers floating around your safe. Constructive intent and all :rolleyes:
Yes, but as has been mentioned, don’t get caught with additional unregistered lower(s) that do not have an attached 16"> upper though. If you only have one registered lower then you are ok with several short uppers other than the length you listed on your form 1 or 4 & different calibers if you so chose. If it’s gonna be a permanent length change other than what you’ve listed the ATF asks that you send them a letter advising such so they can annotate this in the registry.
Thanks for the quick replys.
Is there a ATF form for listing multi-caliber, or barrel lengths? Or do you just send a well written letter advising them that you want to run several calibers and Bbl lengths?
Swapping an upper is not a permanent modification. Several of my Title II dealers have told me they have letters stating that non-permanent alterations to firearms like the AR or M16 do not need letters to the NFA branch “asking for permission”.
There is nothing stating that you can’t swap uppers in mutliple calibers. It’s not like Rem 700 SBR where if you changed the barrel it could be viewed as a permanent alteration of its caliber.
Not sure if this was in response to me, but I stated if it’s going to be a permanent change in bbl length they ask that you inform them. Merely swapping uppers back & forth obviously doesn’t fit this. I guess if you have several uppers & then you go to running one length that’s different from what’s listed on the form 1 or 4 the rest of the time you own the registered lower then this could prolly be construed as a permanent change. I’ve never known anyone to be challenged on that by a agent though, so owning mulitiple lengths to swap between isn’t gonna be a prob.
It was a general response, following the thread direction. 
If I already have a registered lower, am I required each time I purchase a new SBR upper, pay a $200 tax?
Not for additional uppers on the same, already registered lower. You do have to pay $200 each time you register an additional lower or other NFA item, i.e., suppressor, etc.
The tax is paid for each SBR (the lower is the SBR) you may have as many other uppers for it as you like.
If I already have a registered SBR lower, would I have to go through a dealer to obtain a new 10.5" upper or can I order it and have it shipped to my home? Thanks.
You can have it sent to your house.
I just sent the ATF a letter about buying a 9mm upper for my SBR.
Below is the letter that I sent to BATF. If you want pm me and I will send it by e-mail.
Luke
Wednesday, August 08, 2007
Reference: Additional Information on my ATF Form 1 (5320.1)
CERTIFIED MAIL
National Firearms Act Examiner
National Firearms Act Branch,
Bureau of Alcohol, Tobacco, Firearms and Explosives
244 Needy Road
West Virginia 25405
Dear National Firearms Act Examiner,
Subject: Additional Information for ATF Form 1 (5320.1)
I have included this attachment sheet for the additional description of the firearm listed in 4h of ATF Form 1 (5320.1). I have listed 5.56 as the caliber because this is the most widely used caliber for this style of firearm. In the future, I plan on buying other upper receiver and barrels group for this weapon. They include the following calibers of upper receiver.
.22 Long Rifle
.204 Ruger
5.56 x 45 mm NATO
.223 Remington
.243 WSM
6.5 Grendael (.264 cal)
6.8 SPC (.270cal)
.300 Wisper
7.62 x 39mm
9mm Parabellum
.45 ACP
45 Bushmaster
.458 SOCOM
.50 AE
.50Beowulf
.50 BMG
I have listed barrel length 11.5” in 4e of ATF Form 1 because this is the length of barrel that I have on order for this receiver. I plan on buying barrels of different lengths that fall with in the National Firearms Act of 1934. They include the following lengths:
7.5”
8.5”
10.5”
11.5”
14.0”
14.5”
These are the possible barrel lengths of upper receivers that I may purchase. The additional over length is related to the various barrel length possibilities. If you have any questions please feel free to contact me either by phone or email at luke.v.keating@xxxxxxx.xxx xxx-xxx-xxxx cell or my home at xxx-xxx-xxxx.
Additional Description of Firearm Serial Number xxxxxx
Additional Markings
On right side of receiver on the Magazine well “SFC Luke V. Keating (Ret) Trust”
Midland, Ga
If this is with BATF guidelines and regulation could you sign and return this Letter of Amendment with my ATF Form 1 (5320.1) so that Local, State and Federal Law Enforcement Agencies are not confused about the SBR with Serial Number 27474.
By authority of the Director, Bureau of Alcohol, Tobacco, Firearms and Explosives, this amendment has been examined and the applicant’s making and registration of the firearm described above is:
Approved (With the following conditions, if any) Disapproved (For the following reasons)
Authorized ATF Official Date:
Respectfully yours,
SFC Luke V. Keating (Ret)
US Army Retired
Are any of the changes listed in that letter considered permanent?
If not, I’m entirely confused by the recent influx of people wanting to get “permission” letters for non-permanent modifications.
Pure and simple…fear.
Same reason why some people photo copy their form 4s to fit in their wallet, stocks, underneath the brim of their hat so just incase ANYONE asks about your paperwork you have it…
purely speculation 
What about printing a copy, rolling it up and putting it in the tube of my LMT stock? Works.