Rifle barrel length

[Independence]

What is the legally defined way of measuring barrel length of a rifle with permanently attached muzzle device? This is for an Ar15 upper.

I'm only asking this because I've had 2 IPs state to different ways of determining that length. One said start from the beginning of the rifling in the barrel, one stated from the beginning of the receiver.

 

[danb]

From Ch2 of ATF NFA handbook:

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 The rod is then marked at the furthermost end of the barrel or permanently attached muzzle device, withdrawn from the barrel, and measured.

https://www.atf.gov/firearms/national-firearms-act-handbook

One said start from the beginning of the rifling in the barrel, one stated from the beginning of the receiver.

 

[Tungsten]

I've always been told it is from the tip of the permanent attached hider to the face of the closed bolt

 

[Boats]

I've always been told it is from the tip of the permanent attached hider to the face of the closed bolt

this

 

[Independence]

Okay, I wasn't losing my mind when i heard their answers. That's exactly what I've found online. I told the one IP that it was from the bolt face and he kept insisting it was from the receiver.

Thanks.

 

[danb]

I don't understand how FFLs can get this wrong. Its pretty clear and on the ATF website. Nor is this a new rule. Its also scary that 2 IPs got this wrong.

 

[lazarus]

One note, that’s for rifles. And semi-automatic pistols. Revolvers are measured from the end of the barrel to the start of the forcing cone. not the breach/bolt face.

So a 1 3/8” snubbie barrel is actually that long. A 2.5” semi-auto 9mm has a barrel approximately 1.5” in length (about 1” chamber).

This also means that a 16” AR-15 .223 barrel has a different length rifled length than a 16” AR-10 .308 barrel (because the .308 chamber is a little longer than the .223 chamber)

 

[Park ranger]

One note, that’s for rifles. And semi-automatic pistols. Revolvers are measured from the end of the barrel to the start of the forcing cone. not the breach/bolt face.

So a 1 3/8” snubbie barrel is actually that long. A 2.5” semi-auto 9mm has a barrel approximately 1.5” in length (about 1” chamber).

This also means that a 16” AR-15 .223 barrel has a different length rifled length than a 16” AR-10 .308 barrel (because the .308 chamber is a little longer than the .223 chamber)

Very good points. And I like that you said rifled length. The "barrel " is the same , but chamber takes away from rifle sections. Same could be said for a long throat 308 set up for 220's vs a 308 set up for 155 palma.

 

[calicojack]

From Ch2 of ATF NFA handbook:



https://www.atf.gov/firearms/national-firearms-act-handbook

Does MSP use the same standard to determine barrel length?

 

[DutchV]

ATF inspectors use check rods that are 16" long. They drop the rod down the barrel, onto the closed bolt, and see if it sticks out past the end of the muzzle.

 

[calicojack]

And for overall length:

The overall length of a weapon made from a shotgun or rifle is the distance between the extreme ends of the weapon measured along a line parallel to the center line of the bore.

Hopefully MSP uses the same definition. OBTW - for overall length, where does it say the muzzle device must be permanently attached? Barrel length yes - but overall length???

 

[lazarus]

And for overall length:

The overall length of a weapon made from a shotgun or rifle is the distance between the extreme ends of the weapon measured along a line parallel to the center line of the bore.

Hopefully MSP uses the same definition. OBTW - for overall length, where does it say the muzzle device must be permanently attached? Barrel length yes - but overall length???

That’s what ATF uses.

 

[DutchV]

And for overall length:

The overall length of a weapon made from a shotgun or rifle is the distance between the extreme ends of the weapon measured along a line parallel to the center line of the bore.

Hopefully MSP uses the same definition. OBTW - for overall length, where does it say the muzzle device must be permanently attached? Barrel length yes - but overall length???

Overall length doesn't include muzzle devices unless they are permanently attached.

 

[Pinecone]

Overall length doesn't include muzzle devices unless they are permanently attached.

The same for barrel length.

 

[Slowhand]

Phased plasma rifle in the 40 Watt range? Asking for a friend.

 

[Biggfoot44]

Unless that 1 3/8 in snub is a NAA Mini revolver , that sounds like the measurement from muzzle to frame . A "2 inch" J frame is either 1 7/8 or 2 1/8 , depending if it is std or "magnum" frame .