Measuring barrel length with an adjustable choke

[Ivy Mike]

I know that the ATF measures from the bolt or breech face. My question is what pieces count as barrel length?
Specifically, I have JC Higgins Model 20 with a 27" barrel IF I measure to the end of the choke adjustment collar with my tape measure. I'm assuming that since the collar portion is not permanently affixed, it wouldn't be counted in the measurement, but the piece that it screws onto, is permanently affixed. Does that count? Or is it just to the end of the original barrel without the added choke pieces?

The gun itself seems to have been sold as having a 26" barrel, so I'm not quite sure what to make of this. I have been considering cutting it down to make it a more home defense oriented gun and want to make sure I don't make it into an NFA weapon and myself into a felon.

Or should I just write to the ATF and include some pics?

 

[Virginian]

From the end of the choke tube collar device to the breech face.

 

[Riomouse911]

As was stated by Virginian: measure from the breech face to wherever the pieces remain affixed to the barrel from the detachable choke (if applicable).

With the gun unloaded and the barrel mounted, I close the action and insert a dowel that's longer than the barrel into it. I mark the dowel where the end point is with a pencil (End of the barrel or permanently affixed portion of the choke), then withdraw the dowel and use a measuring tape to measure the distance between the end of the dowel and the mark.

For legal purposes; if the choke is permanently "pinned", such as "drilled, pinned, welded over" or high-temperature silver soldered on, it would be measured to the end of the pieces of the choke that remain permanently attached to the muzzle. (Like a 14.5" AR barrel with a Phantom flash hider pinned/welded on, it's now considered to be over the 16" minimum even though the actual "barrel" is still only 14.5" long. ) If the choke comes completely off the barrel by unscrewing it, then take it off and measure to the end of the barrel.

Stay safe.

 

[George P]

If you're going to cut it down, it really doesn't matter because you'll be cutting that adjustable choke device off anyway.

 

[Cvans]

When in doubt leave it a little longer than the requirements. It's a real bummer to find out after you cut it that your a 1/4 inch short.

 

[1KPerDay]

NFA won’t care if it’s 26” or 27” or 25”.
They get interested if it’s 17.8” though.

 

[jmr40]

I've cut a couple of 870 Express barrels down. With the vent rib you have to cut at one of the posts supporting the rib. To be legal I could cut at 19" or 21". The next rib would have left the barrel at 17". I chose to cut at 21". My logic was that if I messed up, or didn't like it I had one more chance to cut at 19". I found 21" to be short enough. I also have a 20" rifle sighted slug barrel for it. I just prefer having a bit more barrel than the legal minimum of 18". My advice is to make the initial cut at closer to 20" and see how it works for you. You can always go shorter if you don't. Most from the factory actually measure 18.5" just to be safe anyway.

 

[bearcreek]

I know that the ATF measures from the bolt or breech face. My question is what pieces count as barrel length?
Specifically, I have JC Higgins Model 20 with a 27" barrel IF I measure to the end of the choke adjustment collar with my tape measure. I'm assuming that since the collar portion is not permanently affixed, it wouldn't be counted in the measurement, but the piece that it screws onto, is permanently affixed. Does that count? Or is it just to the end of the original barrel without the added choke pieces?

The gun itself seems to have been sold as having a 26" barrel, so I'm not quite sure what to make of this. I have been considering cutting it down to make it a more home defense oriented gun and want to make sure I don't make it into an NFA weapon and myself into a felon.

Or should I just write to the ATF and include some pics?

As has been said, at the current length, there's no particular reason, other than curiosity, to measure the barrel "properly". If you're going to cut the barrel down and then remount the adjustable choke on it, then you'd need to worry about measuring it. Was that your plan? If so, I'd suggest skipping that and just threading the barrel for choke tubes, if you want the ability to change chokes.

 

[Carl N. Brown]

ATF counts as barrel any permanent barrel attachment that cannot be removed except by sawing,

Local guy bought a Winchester Model 12 at a prison surplus auction. Suppose to be 18" but was actually shorter when he measured it. He called the local ATF offoce and asked them what to do. They advised that he immediately remove the barrel from the gun and take it to a gunsmith and have an extension permanently attached to the barrel. As I recall, he had a Cutts compensator (an antique muzzle brake) permanently attached.

 

[kBob]

That's "Classic Muzzle Break", Carl. ;-)

-kBob

 

[Ivy Mike]

If you're going to cut it down, it really doesn't matter because you'll be cutting that adjustable choke device off anyway.

Right, but I'll need to measure the full length, then measure back from the muzzle to determine where to cut. So I will need an accurate measurement to begin with.
I don't particularly care about being able to choke it down at the ranges it (hopefully never) will be used.

 

[bearcreek]

Right, but I'll need to measure the full length, then measure back from the muzzle to determine where to cut. So I will need an accurate measurement to begin with.
I don't particularly care about being able to choke it down at the ranges it (hopefully never) will be used.

You need an accurate measurement, not a legal one. Just don't mess with the choke in between measuring the barrel and marking it to cut.

 

[danez71]

Right, but I'll need to measure the full length, then measure back from the muzzle to determine where to cut. So I will need an accurate measurement to begin with.
I don't particularly care about being able to choke it down at the ranges it (hopefully never) will be used.

I think I get what you're saying.... but no you dont.

• Unscrew everything that's not permanent.
• Mark dowl at your desired post cut barrel length with fudge factor as warranted.
• Stick dowl in barrel and mark current length.

Measure distance between 2 lines and there you go.


I could be reading wrong but in the OP, there seems to be a question of what was `it sold as` vs. what `it actually is`.

What is actually is after you cut it is what matters most so I would use the above to get the measurement you want.

 

[Ivy Mike]

I think I get what you're saying.... but no you dont.

• Unscrew everything that's not permanent.
• Mark dowl at your desired post cut barrel length with fudge factor as warranted.
• Stick dowl in barrel and mark current length.

Measure distance between 2 lines and there you go.


I could be reading wrong but in the OP, there seems to be a question of what was `it sold as` vs. what `it actually is`.

What is actually is after you cut it is what matters most so I would use the above to get the measurement you want.

You're describing the same thing I did, but I used a tape measure. I don't need a dowel rod.
1. Measure full length of barrel. Mine comes to just under 27" with the attached adjustable choke. That was the question, from what point do I have to measure, the permanently affixed part or the removable part?
2. Measure from the muzzle back to the point you want to cut. In my case, I will measure back about 8.5" to give myself the extra length for a total of 18.5" Mark it there. 27 - 8.5 = 18.5. On mine, the permanently affixed portion is close enough to the end of the remvable bit that 1/2" of fudge still leaves me well within the legal finished length.
3. Tie a string around the current front sight and stretch it back across the top of the receiver sight grooves, and mark the center line.
4. Stick the thing in the chop saw, ensure the blade is perfectly perpendicular to the barrel and buzz the barrel off.
5. Deburr and recrown the barrel. Install new front sight along previously established center line from step 3.

et voila! New home defense shotgun made from a bird gun I've never actually hunted with.

 

[danez71]

You're describing the same thing I did, but I used a tape measure. I don't need a dowel rod.

Well, sure. Technically that would be easier.

 

[bearcreek]

You're describing the same thing I did, but I used a tape measure. I don't need a dowel rod.
1. Measure full length of barrel. Mine comes to just under 27" with the attached adjustable choke. That was the question, from what point do I have to measure, the permanently affixed part or the removable part?

The reason you use a dowel rod is because the barrel is supposed to be measured from the bolt face. Most tape measures don't fit down the barrel and it's tough to tell exactly where the bolt face is from the outside of the barrel. The position of the adjustable choke doesn't matter as long as it remains the same throughout the measuring, marking and cutting process. Simply treat the barrel as if the adjustable choke didn't exist but was a regular style barrel.

 

[Ivy Mike]

The reason you use a dowel rod is because the barrel is supposed to be measured from the bolt face. Most tape measures don't fit down the barrel and it's tough to tell exactly where the bolt face is from the outside of the barrel. The position of the adjustable choke doesn't matter as long as it remains the same throughout the measuring, marking and cutting process. Simply treat the barrel as if the adjustable choke didn't exist but was a regular style barrel.

I know that. It was the first sentence in the first post. I am measuring the same way the ATF does, from the bolt face.
I have a small tape measure that fits down the bore. A plain old Stanley 10ft tape I've had for many years.
If the adjustable choke collar is not supposed to be included in the measurement, then measuring from it could make the actual length of the cut barrel too short. For example, if you start with 24 inches, measure back 6 and cut, you'd have 18. But if your measure included and adjustable choke that was removable and not counted in the overall ATF measurement, your barrel could now be too short and you'd need to either add a permanent extension or replace the barrel or disassemble everything until your SBS paperwork and $200 tax stamp go through.
Hence the reason I asked about removable devices.

 

[bearcreek]

For example, if you start with 24 inches, measure back 6 and cut, you'd have 18. But if your measure included and adjustable choke that was removable and not counted in the overall ATF measurement, your barrel could now be too short

You're not following the math man. I could add 6 feet of removable pipe on the end of the barrel, measure back, subtract 18.5" and I know how much to cut off. Whatever is on the end of the barrel and whether or not it's adjustable is irrelevant as long as it remains consistent and un-adjusted between measuring the inside of the barrel and measuring the outside. Tell you what, if it makes you feel better, just cut the adjustable choke off right behind the collar and then do your measuring and cut again.

 

[Ivy Mike]

You're not following the math man. I could add 6 feet of removable pipe on the end of the barrel, measure back, subtract 18.5" and I know how much to cut off. Whatever is on the end of the barrel and whether or not it's adjustable is irrelevant as long as it remains consistent and un-adjusted between measuring the inside of the barrel and measuring the outside. Tell you what, if it makes you feel better, just cut the adjustable choke off right behind the collar and then do your measuring and cut again.

I'll just unscrew the collar if it makes you feel better about repeating what I already said.

 

[bearcreek]

I'll just unscrew the collar if it makes you feel better about repeating what I already said.

Just trying to help you understand the math. Tough to do this sort of thing via print. There is zero reason, other than simple curiosity, to figure out what the current legal length of your barrel is.

 

[I6turbo]

When I shortened the barrel to 18.25" on my 1954 model Auto 5 and made my first HD type shotgun, I didn't envision shooting it very much. Then after I took it out it quickly became one of the guns that I want to take out and shoot every chance I get. I sent the barrel to Michael Orlen and had screw-in sporting clays chokes installed. Then I built a similar one from a 1952 Model 37. I generally like shooting these guns better than my full length shotguns, and they'd be a couple of the last guns that I'd voluntarily let go.

 

[JohnKSa]

ATF counts as barrel any permanent barrel attachment that cannot be removed except by sawing...

Correct. If it's not a permanent part of the barrel then it doesn't count towards the length.

Permanent means permanent. If you can remove it without cutting/torching/sawing then it's not permanent.

 

[Drail]

l6turbo - AYE CHIHUAHUA!!! - that 1954 Auto 5 is one handson shotgun. I am drooling all over my keyboard. How do I get in your will? I love the M37 too. You have EXCELLENT taste.

 

[I6turbo]

^^ Haha! Thanks. I'll have to give the will question some thought...

 

[Drail]

Just funning ya. That is a nice pair though.