Form 1 Barrel Length Question

[calicojack]

Probably a dumb question . If I am adding an extension to a barrel to increase the rifle OAL, say a 1" extension to an 8" barrel, do I enter 8 for the barrel length or 9?

 

[Squaregrouper]

Probably a dumb question . If I am adding an extension to a barrel to increase the rifle OAL, say a 1" extension to an 8" barrel, do I enter 8 for the barrel length or 9?

Barrel length is based upon permanent length. If not pinned/welded or silver brazed, the length is to the end of the threads- muzzle device is not included.

 

[calicojack]

Barrel length is based upon permanent length. If not pinned/welded or silver brazed, the length is to the end of the threads- muzzle device is not included.

Ok. I have an 8" barreled AR pistol - but - I am using a Just Right Carbine buffer tube (for the SBR) that is 1" longer (will have to add a spacer behind the buffer spring) and will make up the difference with a barrel extension. So that will have to be like 9.5" or so after permanent attach. I will need to do some measurements. Thanks.

 

[Squaregrouper]

Ok. I have an 8" barreled AR pistol - but - I am using a Just Right Carbine buffer tube that is 1" longer (will have to add a spacer behind the buffer spring) and will make up the difference with a barrel extension. So that will have to be like 9.5" or so after permanent attach. I will need to do some measurements. Thanks.

I am the MDS'er who proved a JRC buffer tube and a long LOP buttstock can get a 8.5" barrel to 29" OAL. Look into the longest LOP AR stocks and I'm sure you can pull it off. Luth AR makes a really long one.

 

[jrumann59]

Stock and pin and welded muzzle device can get you there.

 

[smokey]

Bloodline 10.5" 300 Blackout Barrel | Rosco Manufacturing

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Probably less effort just to swap to a 10.5

 

[outrider58]

Bloodline 10.5" 300 Blackout Barrel | Rosco Manufacturing

Browse Rosco Manufacturing's Bloodline Barrels | 10.5" 300 Blackout Bloodline Barrel for sale | 10.5 Inch 300 BLK Barrel | Suppressor friendly and accurate

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Probably less effort just to swap to a 10.5

^^^This. There is no shame in having a 10.5" barrel on an SBR.

100 yard groups through my 10.5 300 Blk SBR, both supers and subs...

 

[Samlab]

Don’t quote me on this but I thought your minimum barrel length on a SBR is 10”. Overall length of the SBR is 29” for MD. So if your barrel is 8” and you weld, silver solder or blind pin a 2” break/extension to the barrel your good to go.

 

[calicojack]

It's a CMMG radial delayed blowback 45 ACP so barrel choices are limited.

 

[calicojack]

I am the MDS'er who proved a JRC buffer tube and a long LOP buttstock can get a 8.5" barrel to 29" OAL.

Yep. I saw it and ordered one. I think it was a thread for an MP5 pistol (?). I forget.

 

[calicojack]

Bloodline 10.5" 300 Blackout Barrel | Rosco Manufacturing

Browse Rosco Manufacturing's Bloodline Barrels | 10.5" 300 Blackout Bloodline Barrel for sale | 10.5 Inch 300 BLK Barrel | Suppressor friendly and accurate

www.roscomanufacturing.com

Probably less effort just to swap to a 10.5

^^^This. There is no shame in having a 10.5" barrel on an SBR.

100 yard groups through my 10.5 300 Blk SBR, both supers and subs...

View attachment 397445 View attachment 397446

I could always use an extra 300 Black upper. But yeah - this one is a CMMG 45ACP.

 

[calicojack]

Bloodline 10.5" 300 Blackout Barrel | Rosco Manufacturing

Browse Rosco Manufacturing's Bloodline Barrels | 10.5" 300 Blackout Bloodline Barrel for sale | 10.5 Inch 300 BLK Barrel | Suppressor friendly and accurate

www.roscomanufacturing.com

Probably less effort just to swap to a 10.5

Well - this brings up a great point. I could re-purpose the lower all together. But no, I already sunk a bunch of money into this thing, and it is a ton of fun to shoot. I am concerned about a barrel extension not being straight and causing a baffle strike. So if this can be solved by a 16" LOP, whatever, I'd rather do that.

 

[calicojack]

Wow - this Luth AR MBA-1 Rifle Buttstock would certainly get me there. Kind of a grandiose butt stock for this kind of rifle, but I could always replace it when I retire out of state.

 

[calicojack]

And yes - ATF Form 1 is pending and will be submitted once I know the barrel length I am using.

 

[outrider58]

I could always use an extra 300 Black upper. But yeah - this one is a CMMG 45ACP.

My bad. I saw Smokey's post and reacted to that.

Me, I'm keeping my pistols as pistols until which time, I can leave this paradise know as Merryland. Then I will SBR them, which was always my want.

 

[outrider58]

Probably a dumb question . If I am adding an extension to a barrel to increase the rifle OAL, say a 1" extension to an 8" barrel, do I enter 8 for the barrel length or 9?

Is there a barrel extension that will work on your gun?
Are you suppressing your 'pistol'? A tri-lug adapter would add length as well as functionality. Obviously it would have to be permanently attached.

3-Lug Muzzle Device - SilencerCo

The .45 caliber 3-Lug Muzzle Devices must be used only with .45 caliber 3-Lug Mounts. The 9mm 3-Lug Muzzle Devices must only be used with 9mm 3-Lug Mounts.

silencerco.com

 

[Bountied]

Do not comply. The letter hasn't even been filed yet and everyone's shitting their pants. You still have 120 days after it's official. I'm holding to see what happens.

 

[smokey]

It's a CMMG radial delayed blowback 45 ACP so barrel choices are limited.

Oh dip, awesome gun.

 

[calicojack]

Me, I'm keeping my pistols as pistols until which time, I can leave this paradise know as Merryland. Then I will SBR them, which was always my want.

I think this is a great strategy, but it's not clear to me any more what constitutes a pistol configuration for an AR and how that may change yet again in the future. From a shooting standpoint, I am not a fan of pistol braces, but am glad we adopted them as an alternative for shooters that do find them useful. I like the three lug you posted.

 

[Squaregrouper]

I think this is a great strategy, but it's not clear to me any more what constitutes a pistol configuration for an AR and how that may change yet again in the future. From a shooting standpoint, I am not a fan of pistol braces, but am glad we adopted them as an alternative for shooters that do find them useful. I like the three lug you posted.

SD Tactical has them on closeout.
.

3-lug Muzzle Breaks Carbon Steel Black | SD Tactical Arms

Our 3-lug muzzle device is designed to quick connect or disconnect with our 3-lug mount. These muzzle breaks are made of carbon steel, and are designed for use with 9mm platforms.

sdtacticalarms.com