Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login
Site Notices
Posted: 8/24/2004 7:15:08 AM EST
What is the exactl legal barrel lenght for an m4"
Link Posted: 8/24/2004 7:19:42 AM EST
That would be 14.5".

Mike
Link Posted: 8/24/2004 7:20:12 AM EST
same as any other rifle. 16".
Link Posted: 8/24/2004 7:21:48 AM EST
actual m4 14.5

legal you can have 16" unless you go the SBR route.
Link Posted: 8/24/2004 7:22:30 AM EST
Bushmaster says 16 in is the legal length, but i thought 14.5 was, but i really didnt know.

Link Posted: 8/24/2004 7:24:57 AM EST
when the ban sunsets will this change?
Link Posted: 8/24/2004 7:26:51 AM EST
[Last Edit: 8/24/2004 7:28:48 AM EST by mr_wilson]
No, legal (non-SBR) length will remain 16".

Mike

added: best you'll be able to do is the 14.5" barrel w/ permanent mounted Vortex or Phantom, which will meet the BATF required legal length
Link Posted: 8/24/2004 7:28:35 AM EST

Originally Posted By ST5Terminator:
Bushmaster says 16 in is the legal length, but i thought 14.5 was, but i really didnt know.





The militarys Real M4 is 14.5 with a A2 flash suspressor. Civies can't just have a 14.5" barrel unless you sbr it. Now you can have a 14.5 as long as it has a ak muzzle brake, vortex fs, phantom fs, or some other variation of brake/fs as long it brings the oal to 16".
Link Posted: 8/24/2004 7:36:54 AM EST
Don't confuse "legal" with "specification".

An M4 barrel as contracted by the US Government is 14.5". That is the "specification" (spec).

However, you or I cannot install one on our AR15s because is is not legal. Under NFA regulations minimum barrel length for a rifle is 16". You can if you register it as a SBR or if you permanently attach a flash hider (pre 1994) or a muzzle brake so that the overall length exceeds 16".

An M4 barrel with a permanently attached "birdcage" flash hider is illegal, as the flash hider is not long enough to bring the OAL to 16". A Phantom on the other hand is OK, as it is much longer.

Due to this little quirk some manufacturers are making M4 type uppers and selling them with muzzle brakes permanently attached. I do not know if anyone makes a 16" threaded barrel
(1.5" longer than spec) with M4 barrel contours so it can be used with a removable brake/flash hider. I would guess there would be a market for such an abomination, just have not looked for it.

Still confused? Blame the BATF.
Link Posted: 8/24/2004 7:40:03 AM EST
[Last Edit: 8/24/2004 8:07:53 AM EST by scrum]
16" total or SBR application.

16"
14.5 + 1.5 permanent attach
11.5 + 5.5 permanent attach
... so long as it meets or exceeds 16"

Some manufacturers make 16" barrels in M4 profile and call them Patrolman Carbine, or similar terms. You can also have a 16" (any barrel over 16" really) turned down to M4 profile.

Registered SBRs are LEGAL, they just require additional administrative and tax hassles. Unregistered SBRs, just like every other NFA item (MGs, DIAS, LLs, etc) are not legal. There may be additional restrictions at the state level, but the Federal regulations boil down to this distinction.
Link Posted: 8/24/2004 7:45:53 AM EST
The other option I've seen is a 15" "M4 profile" barrel (i.e., one with the cutout for mounting an M203). If you permenantly attach an A1 or A2 flash suppressor it comes up to the legal 16".

Also Kurt @ KKF makes a flash suppressor that looks like a long A2 - I think he calls it an A3. If that is perm attached to a "true" 14.5" M4 barrel, you are legal.
Link Posted: 8/24/2004 7:57:21 AM EST
All righty then here is a question, does anyone have a list of flash hiders that are over 1.5" taht would be legal, i.e. bring the over all lengh to 16"? Or perhapse a link to a resource for flash hiders? Thanks :)
Link Posted: 8/24/2004 8:00:57 AM EST

Originally Posted By Eukatae:
All righty then here is a question, does anyone have a list of flash hiders that are over 1.5" taht would be legal, i.e. bring the over all lengh to 16"? Or perhapse a link to a resource for flash hiders? Thanks :)


From Forest; Muzzle Devices
Link Posted: 8/24/2004 10:06:27 AM EST
bushmaster makes a m-4 profile barrel thats 16''. it has the groove for mounting the m203 but their website says its ''stretched'' 1.5''. so thats an option. i say go with a perm. attached vortex.
Link Posted: 8/24/2004 12:39:44 PM EST
I agonized over this myself, and chose the 16" M4 profile with screw-on A2 FS. You never know when you might want to remove that front site, buy a suppressor, or whatever else. Of course now that I've got it (or will shortly) I'll probably never take the damn thing apart.
Link Posted: 8/25/2004 6:25:28 AM EST
[Last Edit: 8/25/2004 6:27:12 AM EST by der_Buschmeistermann]

Originally Posted By norman74:
I agonized over this myself, and chose the 16" M4 profile with screw-on A2 FS. You never know when you might want to remove that front site, buy a suppressor, or whatever else. Of course now that I've got it (or will shortly) I'll probably never take the damn thing apart.



I went the same route, Norman. I figured the extra 1.5 inches might also provide a little more muzzle velocity downrange (however small).
I am still trying to decide whether to mount a Phantom that I have on the end. I am just not sure if it will look too long.
Link Posted: 8/25/2004 6:50:04 AM EST

Originally Posted By norman74:
I agonized over this myself, and chose the 16" M4 profile with screw-on A2 FS. You never know when you might want to remove that front site, buy a suppressor, or whatever else. Of course now that I've got it (or will shortly) I'll probably never take the damn thing apart.



Having the ability to screw off the flash supressor is a big plus. You can build up a lot of crud down there that is hard to clean if it is permanent.
Link Posted: 8/25/2004 6:53:32 AM EST
[Last Edit: 8/25/2004 6:56:41 AM EST by _DR]

Originally Posted By ST5Terminator:
What is the exactl legal barrel lenght for an m4"




for ANY semiautomatic or manual action rifle according to the BATF:

MINIMUM BARREL LENGTH: 16 inches for barrel - tip of muzzle or muzzle device to breech- permanent.
MINIMUM OVERALL LENGTH: 26 inches from end of stock to end of muzzle or muzzle device. If folding stock, this is measured with folding stock fully extended.

Anything less is an SBR (short barrelled rifle), is an NFA item, and needs written approval from the BATF. Registered machineguns are exempt from this rule as they are not considered "rifles" by the BATF.
Link Posted: 8/26/2004 9:45:56 AM EST
[Last Edit: 8/26/2004 9:47:35 AM EST by rgrprib]
I had Bushy perm-pin a Phantom on to a 14.5 to make it legal 16+ inches. Phantom functions great at supressing flash, even with PMC & PMP ammo.

"We the Willing, Lead by the Unknowing, Do what is Necessary, For the Ungrateful"
Link Posted: 8/28/2004 6:36:25 PM EST

Originally Posted By _DR:


MINIMUM BARREL LENGTH: 16 inches for barrel - tip of muzzle or muzzle device to breech- permanent.
MINIMUM OVERALL LENGTH: 26 inches from end of stock to end of muzzle or muzzle device. If folding stock, this is measured with folding stock fully extended.





Silly question here, but does the rifle have to meet both of those requirements, or as long as the overall length is 26 or more with the stock extended, its okay? IE have a little bit shorter barrel, but a little bit longer stock, or something along those lines...
Link Posted: 8/28/2004 6:42:26 PM EST

Originally Posted By Zack3g:

Originally Posted By _DR:


MINIMUM BARREL LENGTH: 16 inches for barrel - tip of muzzle or muzzle device to breech- permanent.
MINIMUM OVERALL LENGTH: 26 inches from end of stock to end of muzzle or muzzle device. If folding stock, this is measured with folding stock fully extended.





Silly question here, but does the rifle have to meet both of those requirements, or as long as the overall length is 26 or more with the stock extended, its okay? IE have a little bit shorter barrel, but a little bit longer stock, or something along those lines...



Has to be both. 16" barrel is a minimum.
Link Posted: 8/28/2004 7:25:52 PM EST

Originally Posted By _DR:
MINIMUM OVERALL LENGTH: 26 inches from end of stock to end of muzzle or muzzle device. If folding stock, this is measured with folding stock fully extended.



I think you mean fully closed, otherwise people would be building 16 inch rifles with 10 inch stock that they wouldn't bother opening.
Top Top