OAL length different than F1...

[Slow Hand]

My F1 shows an OAL of 18" due to my original idea of making a can and pinning and welding to my 8.5" blk barrel. That idea ended up being beyond my capabilities, so I figured to do a 'solvent trap' can and just build baffles for it. It wi end up being around 6" OAL. Do I need to inform the ATF of the change? Is this acceptable? I've always heard/read that you can go shorter but not longer.
Thanks for any help.

[M1-Dan]

To my understanding the OAL that you put is what you can go up to and not exceed that length. But you can go backwards and go shorter.

[Bendersquint]

You can only go shorter than the registered length to accommodate the rethreading of the tube, any further dimensional changes requires a new stamp as the ATF considers it a significant enough event to warrant a new stamp.

So as long as you are within an inch or so you don't need to resubmit.

According to your post your AR would have a barrel length of 26.5" with the can since the can is 18" long.

Dropping from a 18" silencer to a 6" is well into the new stamp range.

I think you filed your form with the wrong measurement, they don't count barrel length on non integral cans.

Time to write the NFA Branch and ask if you can amend your form from 18" to 6" and come up with a crafty reason.

[Slow Hand]

My intent was to make a suppressor that would thread onto and then be pinned and welded to my 8.5" barrel. Not an integral in the true sense of the word, but a permanent part of the barrel negating the need for an SBR stamp. I have since filed another F1 for the SBR stamp with intent to make a shorter can that is of more normal construction. Yep, looks like I'll need to wrote a letter... Anyone have to proper address and anyone specific to attn it to?

[Bendersquint]

My intent was to make a suppressor that would thread onto and then be pinned and welded to my 8.5" barrel. Not an integral in the true sense of the word, but a permanent part of the barrel negating the need for an SBR stamp. I have since filed another F1 for the SBR stamp with intent to make a shorter can that is of more normal construction. Yep, looks like I'll need to wrote a letter... Anyone have to proper address and anyone specific to attn it to?

Not sure off the top of my head but it is the Needy Road address.

For the future they don't care for how long it is with the barrel, they just care about how long the silencer is.

The ONLY time they care about the OAL to include the barrel is with a full length tube integral.

What you are describing in their eyes would be a can pinned/welded to a short barrel to avoid the SBR stamp.

[T-Rex]

Why don't you do the pin and weld, as Bender described, and cancel the SBR Form 1?

That extra $200 can go towards another suppressor form

[Bendersquint]

Why don't you do the pin and weld, as Bender described, and cancel the SBR Form 1?

That extra $200 can go towards another suppressor form

Still has to correct the OAL on the can since his can was intended to be 8.5 not 18"

[Slow Hand]

I just received an email from Gary Schaible from 'ask the experts' and he said I just need to mail a letter to the NFA branch (address on the F1) and notify them of the change in configuration.

[T-Rex]

Why don't you do the pin and weld, as Bender described, and cancel the SBR Form 1?

That extra $200 can go towards another suppressor form

Still has to correct the OAL on the can since his can was intended to be 8.5 not 18"

Yes, understood.
I was just commenting on the extra form for SBR since you covered OAL.

Slowhand,
The letter should suffice. I had to do an amendment, some years ago, on a can that came out 2" shorter.

Bender,
At what distance, shorter than written on the form 1, would you consider the line for amending the form? Any length, 1/4", 1/2", 1"?

[Bendersquint]

Why don't you do the pin and weld, as Bender described, and cancel the SBR Form 1?

That extra $200 can go towards another suppressor form

Still has to correct the OAL on the can since his can was intended to be 8.5 not 18"

Yes, understood.
I was just commenting on the extra form for SBR since you covered OAL.

Slowhand,
The letter should suffice. I had to do an amendment, some years ago, on a can that came out 2" shorter.

Bender,
At what distance, shorter than written on the form 1, would you consider the line for amending the form? Any length, 1/4", 1/2", 1"?

If the OAL changes from what is on the Form an amendment is needed......there is no stipulation stating the minimum length required to amend.