View Full Version : Questions about Short Barrelled M4

April 21, 2009, 05:57 PM
I recently aquired a nice m4 carbine at a gun show. I did not measure it at the show but it appeared to be a 16 inch barrel. However after getting it home and cleaning it I noticed that the barrel ends an inch into the very long flash hider. Measuring from the chamber to the end of the flash hider it only measures 15 inches but measuring from the chamber to the actual end of the barrel (inside the long flash hider) it only mesures about 10 1/2 inches. Now my question is am I correct in assuming that this is actually illegal without the tax stamp from the ATF letting me legally own short barrelled longarms. I am almost thinking that this M4 actually started out as AR pistol that for some reason someone decided to convert over to a rifle.

Willie Lowman
April 21, 2009, 06:04 PM
If the flash hider is permanently attached then it is considered part of the barrel length.

If the flash hider will screw off, the measurement is to the end of the barrel. You can have the FH permanently pinned to the barrel if this is the case.

If the flash hider is removable, separate the upper from the lower and get it out of your house right now. Just having a short upper in a house with a working lower is called "constructive intent" and what the ATF would use to lock you up. Take it to your gunsmith and have a flash hider that will make the over all length 16" pinned in place.

If it is in fact 15", (and you don't have a NFA firearm that it could go on) you are in possession of a rifle that can get you put in the pen.

April 21, 2009, 06:15 PM
The FH will not turn off the barrel, I used a padded strap wrench to attemp to turn it off the barrel and I could not get it to turn. However I also can not see any sort of pin etc that would permanently attach it. As far as overall barrel length, am I correct in assuming that it has to be 16" overall length or longer?

Willie Lowman
April 21, 2009, 06:18 PM
yes. 16" from back of chamber to end of flash hider or have a $200 tax stamp.

April 21, 2009, 06:18 PM
Also, as far as it being modifed. It looks original as the finish is all uniform. Also standard M4 parts fit it such as the handguard which I replaced the standard M4 handguard with a M4 quadrail handguard and it fit perfect.

Willie Lowman
April 21, 2009, 06:22 PM
If it really isn't 16" take it off the receiver. Take the upper to a friend that doesn't own an AR. (it is legal to have a short upper if you don't have the lower)

Find a gunsmith that can remove the flash hider and pin a longer one on... Or get your SBR tax stamp. Just advise. Take it or leave it.

April 21, 2009, 06:29 PM
I guess I am gonna sell it. Anyone that is interested let me know and we can talk details.

[email protected]

April 21, 2009, 07:46 PM
I would also be interested in possible trades as well instead of an outright sale. Rifles I am currently interested in obtaining are another M4, Springfield
M1A, AK47, Russian SVD or Romanian PSL, PTR91, FAL etc. Let me know what you have to trade.

April 22, 2009, 01:37 PM
Wow. So now you are trying to sell a very illegal weapon in a public forum. :eek:

April 22, 2009, 01:47 PM
Curious that a dealer would sell a SBR at a show where the SN is checked (presumably) with a 4473, to someone not in possession of the appropriate paperwork.

Seems like there may be some trolling going on (no offense if not), or you might want to remeasure the bbl. Who is the manufacturer?

Willie Lowman
April 22, 2009, 02:13 PM
Transferring unregistered NFA items is a felony and punishable with 10 years prison and $100,000 fine.

Good luck to you sir.

James K
April 22, 2009, 02:33 PM
Fortunately removing the barrel is easy. Hypothetically, if someone were to find themselves with a short barrel, it could be removed and a new one installed, but it would be best if that hypothetical someone did not mention it to anyone. And of course that hypothetical somone would destroy that hypothetical short barrel.


April 22, 2009, 03:17 PM
Put a cleaning rod down the bore and mark it where the end of the rod is and make sure its seated on the bolt face. Then tell us that its 16.1" to clear yourself then assess what to do next with it. Make sure the flash hider is permanently attached. If its not 16", take the upper to a gunsmith and have it extended and pinned or sell it.


April 22, 2009, 03:38 PM
No actually what I was planning on doing originally was selling it as a short barrelled upper assembly. I guess I should have specified it better in the post, not just in the few emails I recieved. My plan was to get rid of that upper and buy another upper. The 2 halves are currently seperated and in 2 different locations, both out of my house. My intentions were to sell the upper to someone who wanted a short barrel upper and get it properly registered with appropriate paperwork and tax stamp to make everything legal. Also I did take the upper to a gunsmith and according to his measuerment it is exactly 16 inches. He said that it is mesured from the very back of the barrel where the end of the bolt with the 6 or 8 "fingers" that slide through the "fingers" on the chamber which then rotate and lock the bolt. I am not that comfortable with his assumption though because it is open to inturpration and dont want to violate the laws in any way. As far as purchasing it at a gun show and the dealer selling it inappropriately. In my state Dealers who hold a FFL and sell at gun shows are still required to do the background check paperwork etc. On the other hand there are so called "private collection" dealers at gun shows in my state that are only required to verify your age and state of residence. These so called "Private Collection" dealers are not required to do background checks keep paperwork or even write down and retain your name. I got this M4 from a Private Collection Dealers in a trade, I went to the show with a 1941 manufacture Winchester mod 62 22 pump action and traded with this guy to get this M4. He never said anything about it needing a tax stamp etc.

April 22, 2009, 03:46 PM
Also, I am looking into getting a longer barrel installed even though the gunsmith said it measured 16" the way he measured. Theoretically of course.

April 22, 2009, 04:58 PM
Anyways, thank you for everyones input. I have never dealt with any NFA items before and hope to never deal with them again as it is alot of BS to have items that I do not even need. As for the barrel that was in question even though the gunsmith said it was barely legal. This barrel is no more, it has been removed cut in half and the 2 pieces welded together side by side. Needless to say, by next week it will be a muffler on someones new chevy.

April 22, 2009, 06:33 PM
The flash hider was probably permanently attached by a weld of some sort. Don't sell a good rifle just because some here are paranoid. I hope that you are just being paranoid when you said you destroyed the barrel and that you left it intact.

April 22, 2009, 07:25 PM
The flash hider did not appear to be welded and there was no pin whatsoever. From 1st glance it looked to be 16" but upon measuring the outside it was 15" and the gunsmith measured the inside and said it was 16". On the other hand the flash hider was not permanently attached, it appeared to be just threaded although I could not get the flash hider to thread off the barrel.

April 22, 2009, 09:08 PM
A well done silver solder job can't be seen and is perfectly legal.

I've also never seen anything from ATF saying it is a crime to posess a SBR upper if you own a lower unless you put them together.

April 23, 2009, 09:06 AM
I've also never seen anything from ATF saying it is a crime to posess a SBR upper if you own a lower unless you put them together.

It's illegal. They'll charge you with intent if they find both in your house. This is assuming you don't have a legal upper for the lower. If you've got a lower and an SBR upper chilling in your safe, that's where you can get into trouble.

April 23, 2009, 10:08 AM
Do you have a picture of this upper?

April 23, 2009, 10:20 AM
It's illegal. They'll charge you with intent if they find both in your house. This is assuming you don't have a legal upper for the lower. If you've got a lower and an SBR upper chilling in your safe, that's where you can get into trouble.

Please show a link backing up this statement. Are you saying that I can't own both an AR rifle and an AR pistol since the uppers could be swapped?

I've seen that you can't own the full auto conversion parts and the semiauto gun because the only use for those parts is for the construction of a full auto gun (illegal since 1986).

That is not the case for a SBR upper since it is they can be legally owned with the NFA paperwork or installed on a pistol lower without any paperwork.

April 23, 2009, 10:45 AM
Are you saying that I can't own both an AR rifle and an AR pistol since the uppers could be swapped?

No, you can own both, as they've both got dedicated lowers. You can't have multiple lowers without dedicated uppers, and a short barrel upper in the same location, as you could put together an illegal SBR.

April 23, 2009, 10:57 AM
I'd like to see something from ATF to that effect. The same logic could be used to say it's illegal to own a short barrel, even if it wasn't installed in an upper or even a hacksaw and a rifle since the hacksaw could be used to make it into a SBR.

April 23, 2009, 11:33 AM
It's called constructive possession and people have been prosecuted. If you want to research case law yourself you can find the actual cases.


April 23, 2009, 11:50 AM
I have been researching it and haven't seen anything, other than internet lay opinions, that say that owning a Short barrel upper and a lower constitutes constructive posession of an SBR if they aren't assembled and/or stored together.

Regardless, the now destroyed barrel probably had a flash suppressor permanently attached and was completely legal anyhow.

April 23, 2009, 03:41 PM
When all this was going down, I had immediately seperated the upper from the lower and took both halves to 2 different locations out of my house. I am a law abiding gun owner and have absolutely zero intention of ever violating the law in any way. When I offered it for sale or trade I should have specified in the post like I did in the 2 emails I recieved about this. I was only offering the upper for sale as to my knowledge it is legal to own or purchase a SB upper if you do not have the lower in your possession. I told the 2 people who emailed me I would only sell both the upper and the lower if I could have legally taken it to a class 3 FFL holder who could then legally transfer it without me violating any laws. When I decided this was alot more trouble than it was worth. I then told my friend who was holding the upper for me to destroy the barrel. Today he told me tht he was able to remove the barrel and all the parts. The flash hider was held on with some sort of pin on the inside of the flash hider and something like loctite. Anyways, the end result of it was the upper was actually a AR15 pistol upper that the previous owner installed on a rifle lower then had a long flash hider made and attached to the pistol barel. Needless to say after his discovery he decided not to destroy the barrel and just disassembled it then he returned the parts to me minus the barrel and instead of destroying the barrel he kept it for a pistol he plans on building. This was a 10 1/2" pistol barrel with a 6" flash hider pinned to it making it barely legal. I just did not need the BS involved with an item like this so now I am going to need to buy a new barrel as I would prefer to be on the safe side than risk violating any laws.

April 23, 2009, 03:44 PM
As a result of this problem, from now on I plan on taking a dowel rod and tape measure with me to any gun shows as to avoid a potential repeat problem. Also, it is people like this who deceive people and sell them questionable items that are the cause of alot of the problems that plauge shows and result in new laws that make our rights slowly disapear.