M*CARBO Brotherhood

Form 1 Integral Supressor?

Has anyone done one? I’m in the process of designing one and hopefully starting this project soon.

My question is how to fill out the form 1 for the length box? Would it be the sleeve length or the barrel length? There is also an overall length box.

My plan is to start with a TC R22 action, hogue stock, and mill a bull barrel into a integrated muzzle break and then sleeve the break area. I’m thinking this will be the easiest way to go and keep from having to file for a SBR stamp as well as a Supressor stamp.

This will be my first foray into NFA toys so I’m not sure exactly how to get the paperwork correct.


@MrMachinist Are you building the suppressor from scratch and then putting it on a rifle or making the barrel/suppressor shorter than 16 inches and making an SBR? If you are making the barrel/suppressor from scratch and the length is 16 inches or longer, then it should just be one form 1 of the barrel/suppressor and the overall length of just that. If you are making it shorter than 16 inches, then the process should be one form 1 for the barrel/suppressor and then once that clears then a second form 1 for the SBR you plan to put it on. I could be wrong and you might be able to submit both form 1s at the same time but it should definitely be two form 1s for the barrel and then for the SBR. I’m not a lawyer and I’m just going off my personal understanding. YMMV…


It’s going to be an 18” barrel that I will modify into a Supressor. The barrel will still be 18” when I am done but the functional length of the barrel will be around 10” to keep the bullets sub sonic. Similar to the gemtech mist system but instead of a baffle assembly being pinned to the short barrel, mine will just be all one piece.

I can’t get any real answers on how to fill out the length boxes on the form 1.

So I would just put the barrel length in the box? Not the tube length?


@MrMachinist If only part of the barrel is suppressor but the barrel has been permanently modified to be integrally suppressed, then the entire barrel is considered a suppressor. It would be similar to ordering a premanufactured suppressed barrel online. I would call ATF and ask them what they want measured. Also, there’s no “functional length” exemption. Think a 14.5 inch barrel with a pinned and welded muzzle brake to meet the 16 inch standard and avoid NFA. The barrel is only 14.5 inches but the overall is 16.

1 Like

you will have to call the BATF on that one. from my understand of this, and i went down the build own suppressor rabbit hole once, but I built a separate suppressor(my one and only build) I had to submit my drawings/plans with my form one, and the suppressor had to be stamped/marked within the BTAF regulation regarding depth and size.
your going even deeper into the rabbit hole than i did.
ensure that nothing, not a wipe baffle or piece of metal has been touched on this till after paperwork is approved and received.
on your one piece you need to contact BTAF directly, and it depends solely on their interpretation of the guidelines whether your barrel remains a 18" or becomes a 10"SBR which will require a separate tax stamp.
are you slotting the barrel or are you angle drilling the barrel, to what diameter hole
all depends on what your drawings say, whether it changes the rifling profile , as to what the barrel length will be.
here is 1 interpretation from USA Carry,:: if it was integrally suppressed, the barrel is treated as the suppressor for NFA purposes. you would then need one stamp to posess
the integrally suppressed barrel/upper and then one stamp (for a total of 2) to put that barrel/upper on a rifle or stocked lower::
to keep your tail out of a crack, talk to BTAF and get a signed letter stating your requirements for later use.


@goblin I’m not so sure about that part. Putting a suppressor/barrel on a non NFA stock/lower/rifle should not require a second stamp. An integrally suppressed barrel is still just a suppressor and doesn’t change the configuration of a firearm to NFA. The barrel/suppressor is the NFA item not the entire rifle. Hence why the barrel/suppressor would require a separate serial number from the rifle.


@MrMachinist as @GOBLIN and I both stated though, your best course of action is direct contact with the ATF. NFA is a fickle mistress and not to be taken lightly. :+1:t2:


it all depends how BTAF interprets his barrel modification. like i said, i been down that rabbit hole once, slightly. its far easier(and cheaper if you have to go to court over a interpretation) to buy a suppressor than it is to build your own.
thats why i said signed letter by agent that approves it.
in case you need it at a later date, for a agent that looks at it a different way… gotta watch your back with those people. they will bite you.


Looks like talking to them directly will be the best route. If I was just building a can, it’s pretty clear cut, but the direction I want to go is a little different but I think I will be happier in the end.

The barrel modification shouldn’t be an issue because the barrel will be one piece of steel that cannot be shortened to under 16” without cutting it. It’s basically building an integeral muzzle break. Throwing a sleeve on it will make it a suppressor and the sleeve will be the serialized item just like a commercially available can. The modified barrel itself shouldn’t be illegal nor require a stamp because all it will do it make it louder and produce less velocity than the unmodified barrel.

I’ll get a hold of atf soon and let you guys know what I find out. I’m still playing with the design and coming up with the best method to Mfg the parts.

On a side note, if someone has a 10/22 I would appreciate a measurement from the front of the receiver to the end of the stock. Trying to see how much volume I could create without having to turn a thin walled tube down to .920”.


from what i was told before, and its been a couple of years, it depends on the position of the drilling /porting in conjunction to the rifling for some odd ass reason.
yea, keep us in the loop, i could be temped into doing one on the MKII ruger, depending on the hoops you have to jump thru.(thats whats kept my paws from modifying the 2nd MKII with a integral suppressor)
But Logan is 100% correct. the best and only way is to check with BTAF


@MrMachinist will the sleeve/suppressor portion be permanently attached to the barrel? If permanently attached, the entire barrel is a suppressor. Also, the ATF considers suppressor parts to be NFA controlled. There was a recent ruling on wipes being suppressor parts. So if you modify the barrel to work in tandem with your suppressor portion, then the modified barrel is now a suppressor part. I know it takes the DIY fun out of it but maybe just buying an aftermarket barrel outright would be less of a headache.


there ya go Logan, that whole interpretation of parts gig. call these guys up talk to them. they do it for a living.



Good point.

The sleeve will be removable for cleaning.

It sure would be easier to buy one, but I don’t love the options that are available.

I’ll get in contact with them and see what they say.

I was just curious if anyone on here has ever done this before.


BATFE don’t care about functional lengths. Your entire barrel is a suppressor as described. I’d submit it as 18" ±.

I can tell you from my research not to expect consistency from BATFE. If your plans are clear, it should fly as I suggest.

And … I’m very interested in your project. I have a Marlin Papoose I want to build similarly so this isn’t my first thought exercise on the subject.

I actually read a lot at a forum dedicated to Form 1 builds. You can get an opinion there too but you’ll learn quickly that BATFE is a moving target when innovation and creativity are guests at the party.



I would surely like to know the ruling… As you all aware of my 10/22 Custom Builds (one conversion to .17MH2 with a threaded Beyer barrel.) I had failure to feed issues due to an ‘improperly weighted’ charging handle. I resurfaced my receiver and painted it desert sand while awaiting the barrel re-work. I should have the gun finished and running this weekend. I am looking forward to updating everyone since Clint Beyer has made a ‘small investment’ in my project by running down another charging handle and ‘match fitting’ my barrel. I highly recommend him for your ‘custom barrel’ needs. http://beyerbarrels.com


Thanks @Dred

I had the same experience on the form 1 forums.

How detailed do the plans need to be? I hate to be married to an exact plan.

Can they be vague as in a drawing showing a few baffles or do they need to be dimensioned with every detail documented?


@MrMachinist @Dred

Thanks for the ‘mental picture,’ Milton! I have to express the FOLLY of a bunch of SUITS standing in awe of your mechanical drawing… I am quite sure that your Form 1 will be ‘signed off’ without any hesitation and you will have NO PROBLEMS. Yes, one has to ‘worry’ about dotting their I’s and crossing their T’s but that is their jobs when it comes to the ‘politics.’ I don’t believe INTELLIGENCE is a pre-requisite! It surely is overrated??? :thinking::innocent:


every detail. and any variation will cause a issue. “as per plan” is written in stone.










List material spec as well. if you have a MSDS sheet to go along with the material,that’s even better.

1 Like