View Full Version : Really dumb question about overall lengths.

November 24, 2008, 06:49 PM
The question about rifle overall lengths has started me to wondering. What about machine guns?

A form 4 for a machine gun specifies a specific length. But can you legally swap stocks or just remove the stock entirely? Or can you attach a compensator to the end of the barrel? Reason for asking is that an Uzi SMG can be configured with wooden stock, folding stock, no stock at all or either stock with a recoil pad and can be configured with various compensators and brakes.

November 24, 2008, 09:33 PM
Don't quote me on this.

How I believe it works is that as long as you have the parts to return it to the original configuration on the Form 4, it's OK. I know on SBR guns with easily swapped barrels, like 10/22s, people swap different barrel lengths all the time.

Someone else want to correct me on this?

November 24, 2008, 10:51 PM
As long as it is "readily restored" to the condition on the F1 or F4, you can do whatever. I sometimes put a stock on my SBS 870, my SBS H&R, and sometimes I take the stock off my SBR 10/22 and put a VERY short barrel on.

November 25, 2008, 11:53 AM
If you change the configuration of the weapon ATF says you "should" notify them about the change but it doesn't say you MUST!


When there is a change in the configuration of or a modification to a registered firearm, the registrant should notify the NFA Branch in writing so that the NFRTR can reflect the accurate description of the firearm.

November 29, 2008, 05:01 PM
Thanks for the info folks especially aroundlsu. I really like the original configuration best anyway so I won't be changing it. But its nice to know the procedure just in case.