Question about barrel length on Form 1

cap6888 · May 15, 2016

With the impending 41p bs, I plan on Form 1ing my AR pistol. It has a 7.5 inch barrel. I know I won't make the 29 inch limit without pinning something to the end. My question is, by pinning a muzzle device, do I use that to list the barrel length? Or is it still a 7.5 inch barrel, and the muzzle device is just extra? Thanks

Squaregrouper · May 15, 2016

cap6888 said:
With the impending 41p bs, I plan on Form 1ing my AR pistol. It has a 7.5 inch barrel. I know I won't make the 29 inch limit without pinning something to the end. My question is, by pinning a muzzle device, do I use that to list the barrel length? Or is it still a 7.5 inch barrel, and the muzzle device is just extra? Thanks

As long as an ATF approved method of pinning and/or welding is used, the muzzle device becomes part of the barrel length.

Sticky · May 15, 2016

squaregrouper said:
As long as an ATF approved method of pinning and/or welding is used, the muzzle device becomes part of the barrel length.

^^ this... the whole reason for pinning and welding (permanently attaching) a muzzle device is to increase the length of the barrel per ATF specs. One would not otherwise do so if the barrel met the requirements for length or the overall length of the weapon were not a legal issue.

Many build rifles with a less than 16" length barrel and pin/weld to achieve the 16" min requirement to stay clear of SBR territory.

outrider58 · May 15, 2016

...and in this case, barrel length isn't really the issue, but over all length(''Thanks Captain Obvious!'') so the intent would be to get as close to a 10.5'' barrel as you can assuming you plan on using a standard type collapsible carbine stock. There are longer stocks out there if you still come up a little short. Also, since you are going through the trouble pinning and welding a muzzle device, you might want to use a QD suppressor mount of your choice in the event, later down the road, you want to add a suppressor to your toy chest.

cap6888 · May 15, 2016

Thanks fo the replies guys!

SneakySh0rty · May 15, 2016

squaregrouper said:
As long as an ATF approved method of pinning and/or welding is used, the muzzle device becomes part of the barrel length.

Sticky said:
^^ this... the whole reason for pinning and welding (permanently attaching) a muzzle device is to increase the length of the barrel per ATF specs. One would not otherwise do so if the barrel met the requirements for length or the overall length of the weapon were not a legal issue.

Many build rifles with a less than 16" length barrel and pin/weld to achieve the 16" min requirement to stay clear of SBR territory.

outrider58 said:
...and in this case, barrel length isn't really the issue, but over all length(''Thanks Captain Obvious!'') so the intent would be to get as close to a 10.5'' barrel as you can assuming you plan on using a standard type collapsible carbine stock. There are longer stocks out there if you still come up a little short. Also, since you are going through the trouble pinning and welding a muzzle device, you might want to use a QD suppressor mount of your choice in the event, later down the road, you want to add a suppressor to your toy chest.

Perhaps I am being a stickler (or wrong). I thought, pinning/welding a muzzle device does NOT increase barrel length. What is increases is just your OAL. So, on the form, when it asks for barrel length, it should be still listed as 7.5". Then if you want to, specify pin/weld muzzle device in the addtl. info field. And in the OAL would be however long the pinned muzzle device gets you to (which in MD would have to be 29").

IMO, to try to pin a muzzle device onto a 7.5" barrel and try to reach 29" wont look good. A suppressor mount most definitely wont get you there.

dontpanic · May 15, 2016

SneakySh0rty said:
Perhaps I am being a stickler (or wrong). I thought, pinning/welding a muzzle device does NOT increase barrel length. What is increases is just your OAL. So, on the form, when it asks for barrel length, it should be still listed as 7.5". Then if you want to, specify pin/weld muzzle device in the addtl. info field. And in the OAL would be however long the pinned muzzle device gets you to (which in MD would have to be 29").

IMO, to try to pin a muzzle device onto a 7.5" barrel and try to reach 29" wont look good. A suppressor mount most definitely wont get you there.

Pinning/welding or permanantly soldering a muzzle device increases both barrel length and OAL. That is why we can do this to a 14.5" barrel and end up with a >16" barrel. Keeping us out of NFA territory.

I personally have one 14.5" upper with a pinned welded suppressor mount. It does not need to be put on a SBR /pistol lower. I also have a 14.5" barrel upper with the mount not pinned/welded. This can only be put on a pistol/SBR lower.

Pinning/welding a mount on a 7.5" barrel will get you to about 9". There is a thread around here telling you how to get 29" OAL with a 8.5" barrel. Here it is.

http://www.mdshooters.com/showthread.php?t=191461

Or you could just buy a 10.5" barrel. They tend run better anyway.

Sticky · May 15, 2016

dontpanic said:
Pinning/welding or permanantly soldering a muzzle device increases both barrel length and OAL. That is why we can do this to a 14.5" barrel and end up with a >16" barrel. Keeping us out of NFA territory.

I personally have one 14.5" upper with a pinned welded suppressor mount. It does not need to be put on a SBR /pistol lower. I also have a 14.5" barrel upper with the mount not pinned/welded. This can only be put on a pistol/SBR lower.

Pinning/welding a mount on a 7.5" barrel will get you to about 9". There is a thread around here telling you how to get 29" OAL with a 8.5" barrel. Here it is.

http://www.mdshooters.com/showthread.php?t=191461

Or you could just buy a 10.5" barrel. They tend run better anyway.

Correct.. I recently pinned and welded a qd flash hider on a 14.5" bbl for a friend who wanted to build a rifle, but to keep it light. This will reach the 16" min for a rifle length barrel and weighed in at about 6lbs unloaded.

Per the ATF, if you use their approved method of 'permanent attachment', this creates a longer barrel length (bbl and comp are single unit, stick a dowel in the bbl to the bolt face on a closed bolt, measure the insertion depth = bbl length) and also applies to oal length of the weapon.

outrider58 · May 15, 2016

dontpanic said:
Pinning/welding or permanantly soldering a muzzle device increases both barrel length and OAL. That is why we can do this to a 14.5" barrel and end up with a >16" barrel. Keeping us out of NFA territory.

I personally have one 14.5" upper with a pinned welded suppressor mount. It does not need to be put on a SBR /pistol lower. I also have a 14.5" barrel upper with the mount not pinned/welded. This can only be put on a pistol/SBR lower.

Pinning/welding a mount on a 7.5" barrel will get you to about 9". There is a thread around here telling you how to get 29" OAL with a 8.5" barrel. Here it is.

http://www.mdshooters.com/showthread.php?t=191461

Or you could just buy a 10.5" barrel. They tend run better anyway.

Sticky said:
Correct.. I recently pinned and welded a qd flash hider on a 14.5" bbl for a friend who wanted to build a rifle, but to keep it light. This will reach the 16" min for a rifle length barrel and weighed in at about 6lbs unloaded.

Per the ATF, if you use their approved method of 'permanent attachment', this creates a longer barrel length (bbl and comp are single unit, stick a dowel in the bbl to the bolt face on a closed bolt, measure the insertion depth = bbl length) and also applies to oal length of the weapon.

I too am a member of the 14.5''(+ pinned and welded) club. :party29:

When it comes to non-NFA guns, it is done to achieve 16'' minimum barrel length. With NFA guns(in Merryland), it's a matter of achieving OAL of the SBR.

Sticky · May 15, 2016

See page 6...

https://www.atf.gov/firearms/docs/atf-national-firearms-act-handbook-chapter-2/download

SneakySh0rty · May 15, 2016

dontpanic said:
Pinning/welding or permanantly soldering a muzzle device increases both barrel length and OAL. That is why we can do this to a 14.5" barrel and end up with a >16" barrel. Keeping us out of NFA territory.

I personally have one 14.5" upper with a pinned welded suppressor mount. It does not need to be put on a SBR /pistol lower. I also have a 14.5" barrel upper with the mount not pinned/welded. This can only be put on a pistol/SBR lower.

Pinning/welding a mount on a 7.5" barrel will get you to about 9". There is a thread around here telling you how to get 29" OAL with a 8.5" barrel. Here it is.

http://www.mdshooters.com/showthread.php?t=191461

Or you could just buy a 10.5" barrel. They tend run better anyway.

If you look at the last few post of the thread you will see my measurements and the "YMMV" from the OP.

Sticky said:
Correct.. I recently pinned and welded a qd flash hider on a 14.5" bbl for a friend who wanted to build a rifle, but to keep it light. This will reach the 16" min for a rifle length barrel and weighed in at about 6lbs unloaded.

Per the ATF, if you use their approved method of 'permanent attachment', this creates a longer barrel length (bbl and comp are single unit, stick a dowel in the bbl to the bolt face on a closed bolt, measure the insertion depth = bbl length) and also applies to oal length of the weapon.

I guess I am arguing semantics. As I said before...pinning/welding DOES effect OAL. so pinning to a 1.5 brake to a 14.5 barrel will get you to the 16" OALl. That and a true 16" barrel will give you the same result, no paperwork necessary. BUT what I am arguing is that saying the pin/welded device counts as barrel length, is incorrect.

Sticky · May 15, 2016

SneakySh0rty said:
If you look at the last few post of the thread you will see my measurements and the "YMMV" from the OP.

I guess I am arguing semantics. As I said before...pinning/welding DOES effect OAL. so pinning to a 1.5 brake to a 14.5 barrel will get you to the 16" OALl. That and a true 16" barrel will give you the same result, no paperwork necessary. BUT what I am arguing is that saying the pin/welded device counts as barrel length, is incorrect.

It does... the ATF procedure is very simple... remove any 'removable' muzzle devices from the barrel, stick a rod down and measure to the end of the barrel or permanently attached muzzle devices (if you can't 'remove' the muzzle device, technically it becomes a permanent extension of the barrel and is measured/included as barrel length) and insert it until it hits the bolt face. Mark the rod, remove it, and measure the length to the mark. What is not clear about that?

Sticky · May 15, 2016

I understand your point, but... it's a simple test and if the muzzle device is permanently attached, it is then, in the eyes of the NFA, part of the barrel and included in length (even though it is not rifled, etc...), due to the method used to 'measure barrel length'..

Quoting the NFA doc referenced...

"The ATF procedure for measuring barrel length is to measure from the closed bolt (or breech-face) to
the furthermost end of the barrel or permanently attached muzzle device. Permanent methods of
attachment include full-fusion gas or electric steel-seam welding, high-temperature (1100°F) silver
soldering, or blind pinning with the pin head welded over. Barrels are measured by inserting a dowel rod
into the barrel until the rod stops against the bolt or breech-face. The rod is then marked at the
furthermost end of the barrel or permanently attached muzzle device, withdrawn from the barrel, and
measured."

SneakySh0rty · May 15, 2016

Sticky said:
I understand your point, but... it's a simple test and if the muzzle device is permanently attached, it is then, in the eyes of the NFA, part of the barrel and included in length (even though it is not rifled, etc...), due to the method used to 'measure barrel length'..

Quoting the NFA doc referenced...

"The ATF procedure for measuring barrel length is to measure from the closed bolt (or breech-face) to
the furthermost end of the barrel or permanently attached muzzle device. Permanent methods of
attachment include full-fusion gas or electric steel-seam welding, high-temperature (1100°F) silver
soldering, or blind pinning with the pin head welded over. Barrels are measured by inserting a dowel rod
into the barrel until the rod stops against the bolt or breech-face. The rod is then marked at the
furthermost end of the barrel or permanently attached muzzle device, withdrawn from the barrel, and
measured."

Lessoned learned. I literally just pulled up the pdf on this. thanks for the correction.

Sticky · May 15, 2016

So... to the OP with the original question, if you add a long arsed muzzle device to your 7.5" bbl to get the OAL to the needed requirement, that then needs to be measured after installing the muzzle device and on your form 1, that will be the 'new' barrel length.

If you have a 7.5" bbl, add a 4" long comp or muzzle device to it, permanently attach it and measure, it will be somewhere around 11-11.1" oal (subtract the threaded portion of the barrel, as that is technically not 'adding to the length')

outrider58 · May 15, 2016

SneakySh0rty said:
If you look at the last few post of the thread you will see my measurements and the "YMMV" from the OP.

I guess I am arguing semantics. As I said before...pinning/welding DOES effect OAL. so pinning to a 1.5 brake to a 14.5 barrel will get you to the 16" OALl. That and a true 16" barrel will give you the same result, no paperwork necessary. BUT what I am arguing is that saying the pin/welded device counts as barrel length, is incorrect.

If you are saying that a pinned and welded brake does not "add" to a barrel's length in that the ''working'' part of the barrel is the same length, you are correct. But, that isn't the question the OP was asking. Keep in mind that bbl length is measured from the face of the bolt all the way out to the permanent end of the barrel. In the case of the modern muzzle loader, there is usually an un-rifled inset where you place a bullet to be started. That un-rifled inset is included as to the barrel's length.

Sticky · May 15, 2016

SneakySh0rty said:
Lessoned learned. I literally just pulled up the pdf on this. thanks for the correction.

No problem... it's a weird issue... I agree... the comp ain't 'barrel', but in the eyes of the ATF, it is if it's pinned and welded.

Sticky · May 15, 2016

outrider58 said:
[/B]

In the case of the modern muzzle loader, there is usually an un-rifled inset where you place a bullet to be started. That un-rifled inset is included as to the barrel's length.

Can I SBR my smokepoles? :eek:

outrider58 · May 15, 2016

Sticky said:
Can I SBR my smokepoles?

Quit it Sticky! :rofl:

Sticky · May 15, 2016

outrider58 said:
Quit it Sticky!

Just an aside and back to the OP, I had a 7.5" pistol build and added an old XM-177 'flash hider' to it to tame the muzzle blast and concussion, which was pretty severe with a 5.56 pistol. It was about 5.5" oal and added a good 5" to the barrel length (well, it would if you pinned it, I sold it eventually and went to a 10.5" bbl for the pistol). It worked extremely well to tame that concussion.

Question about barrel length on Form 1

The #1 community for Gun Owners of the Northeast

Member Benefits:

Ultimate Member

Kragaphile

Beware of Dog

Eats Bacon Raw

Ultimate Member

Active Member

Ultimate Member

Beware of Dog

Eats Bacon Raw

Beware of Dog

Active Member

Beware of Dog

Beware of Dog

Active Member

Beware of Dog

Eats Bacon Raw

Beware of Dog

Beware of Dog

Eats Bacon Raw

Beware of Dog

Users who are viewing this thread

Log in

Forum statistics