Detachable buttstocks, Kahr Thompson 'Pistols' and the NFA

[dokkerdam]

I have a few technical and legal questions about Kahr Thompsons and detachable buttstocks. Anyone who might know please feel free to answer.

I want to add a detachable buttstock to my Kahr Thompson, a TA5 'pistol' with a 10.5" barrel. Online I noticed 3 different metal adapter/conversion plates that are made to attach to the rear bottom frame of Thompsons in order to accommodate detachable buttstocks. And I don't want to do anything illegal. Here are my questions:

Is the frame on my Kahr 1927 TA5 pistol aluminum (I believe the receiver is)? If it is aluminum, can these conversion/adapter plates still be installed?

Does the milling and installation (if possible) of the adapter plate make the gun an SBR immediately or do the applicable regulations only apply if I attach a buttstock? (What I'm looking for here as an answer is do I need to apply and receive the required BATF stamps/waiting periods before any machining on the frame is done or can that be done before aquiring and installing a buttstock? If so, can I buy and own the buttstock and not attach it before getting the required BATF approval or does simply owning the buttstock mean I have an SBR?)

There seems to be at least 3 different adapter plates available - one with two screw holes ("stamped?"), one with four holes ("milled?"), and one with six screw holes (probably milled). Is their a preference on these keeping in mind that my frame is aluminum?

Finally, assuming one of the 3 adapter/conversion plates fits and will work on the possibly aluminum frame, will they all fit the new manufacture Kahr detachable buttstock and attaching hardware?

And will the 1928? and other original detachable buttstocks with slide attaching hardware (usually found as 'surplus' covered in arsenal grease) also fit the new adapter plates? Does an old detachable buttstock work on new Kahr SBRs and vice versa?

Last question: Why do some detachable buttstocks come with the crossbolt reinforcement and others do not? Is there a preference here?

Thanks to whoever answer these questions,

dokkerdam

 

(I posted this earlier but was unable to paste the text directly and instead attached a Word file. This is exactly the same post and questions so the old one can be ignored - sorry)

[Black River Militaria CII]

I posted this once to this string, but it didi not take..

You have two choices: replace the short barrel and install a legal length rifle barrel, 16 1/4", or file a taxed form 1 for "making" an NFA registered short barreled rifle, and when you have your approved F1, install the stock mounting hardware and the stock.

As you may know, rifle receivers used to make "pistols", are never assembled with a stock at the factory and may not legally have a stock attached and remain a pistol under federal law. Usually, rifle receivers manufactured for the express purpose of being registered and sold as pistols have their serial numbers recorded as legal pistols by the factory so that if the question arises about the legality of a "pistol", the factory records would verify that it was legally made as one.

FWIW

Edited July 9, 2017 by Black River Militaria CII

[TSMGguy]

https://www.atf.gov/firearms/qa/if-person-has-pistol-and-attachable-shoulder-stock-does-constitute-possession-nfa

 

As an example, I own a Belgian Browning Hi Power 9mm pistol that was produced but never delivered under a foreign contract. It was imported into the US, and so marked. It has tangent sights and a slot for mounting a butt stock. I cannot own such a stock without an approval to make an SBR since this particular pistol is not mentioned in the BATF curio & relics list. Hope this helps!

Edited July 9, 2017 by TSMGguy

[dokkerdam]

Has anybody read the NFA or the GCA of '68 as it applies to these questions. I'm not sure a SBR is an SBR until a stock is attached to it (before they were exempted the Mauser and Luger Artillery pistols were NOT SBRs even though they could accommodate the stock. They became SBRs with the stock attached and then were later exempted). And even more confusing is the definition of a pistol and what Kahr sells as a "Thompson Pistol". Try to shoot the Thompson Pistol, with a loaded 50 round drum (that it was supplied with), with one hand. I don't think it can be done safely. So is the Thompson 'pistol' even a pistol, and with or without a stock is it a rifle? Maybe it's just a "destructive device" (also class III).

[dokkerdam]

thanks to tsmgguy for the info. so is your browning which is very much like the stocked mauser and luger not exempted like they are? and it looks like owning it with the capability to add a stock but not owning the stock is legal. It follows then that if the Thompson pistol were modified with the adapter plates available on-line it would still be a legal non-NFA pistol until I bought or owned an attachable stock. maybe? or I guess to be safe I should get the BATF approval before installing the adapter plate.

thanks,

dokkerdam

Edited July 10, 2017 by dokkerdam

[Black River Militaria CII]

The issue of the A5 has nothing to do with stocked vintage pistols. Only original vintage factory stocks are eligible to be assembled to vintage pistols that are outfitted to hold the stocks. Reproduction stocks are not eligible and require registration with ATF as a short barreled rifle,, with a few exceptions. This has been the law for many years. ATF does not enforce this rather ridiculous law.

A5s are modern pistols made under current ATF manufacturing regs and protocols.

Again, any stocked firearm, shotgun, rifle or other, that left the factory as a stocked firearm cannot legally be converted to a pistol. The virgin receiver MUST never had a stock assembled to be eligible for pistol status under fed law.

An SBR or SBS made from a firearm originally with a longer barrel legally exists as a registered weapon as an assembled combination. Individually, neither a receiver or a barrel can exist as an SBR or SBS.

without being assembled. However, this is an entirely different set of regs compared to attaching a stock to a rifle receiver assembled legally as a pistol with a barrel shorter than the required 16 plus inches.

You can research this on any of the ATF sites.

Various semi-auto "submachine pistols" are being imported for sale in the US. One example is the CZ made PPS43 pistol. It has a stock, but the stock is permanently fixed in the folded position so it cannot be used as a shoulder fired weapon. Another example is the AK pistols which are made without stocks or with folded and fixed stocks.

MP5 SMGs with registered sears in converted lowers present a problem if the lower is removed from the upper. The upper then becomes an SBR. However, the registered lower serves as a positive defense agaInst being in possession of an unregistered SBR.

There are other types of firearms that usually have stocks, but if the receivers leave the factory without ever having had a stock attached, they can leave the factory assembled as pistols or be made into pistols with short barrels by a buyer or gunsmith.

A DD designation only applies to calibers larger than .50 BMG, vintage hunting and sporting rifles exempted. DD status has nothing to do with what you are trying to do........

FWIW

Edited July 10, 2017 by Black River Militaria CII

[dokkerdam]

Thanks. for the info. I read the NFA regs. and the '68 GCA pdf. from the ATF website and am more confused than before.

 

That said, I still don't see the answer to the legal questions I have about whether I can have the frame milled and the adapter plate installed BEFORE getting BATF approval. I'm not trying to get away with anything and I 'll get the required NFA stamp/approval, etc. It's more a matter of the timing and what I can do right away. I don't yet own a compatible stock anyway and I don't want to spend a lot of money on a complete rig before I know I can physically do this.

 

What I'm actually much more interested is the actual ability to attach an adapter plate to what might be an ALUMINUM frame. If that can be done than I would want to know what stocks would fit the modern manufacture adapter plates/kits - do new Kahr and A_Ostocks fit and will surplus and older stocks made way before A-O started up again work.

 

thanks again,

dokkerdam

Edited July 10, 2017 by dokkerdam

[Black River Militaria CII]

Yes, you can do the work on the receiver for assembling the stock mount to it. You only cross the line if you attach the stock without an approved form 1 to "make" an SBR or swap out the barrel for a longer one. This isn't rocket science!

Look, ATF isn't waiting in the bushes to pounce on you. Your activities are of absolutely no importance to ATF whether you comply with the rules or not since there is really no way ATF is going to know if you did or not. You have to do something really, really stupid and have the seriously bad fortune of someone reporting you who knows the rules and notifies the cops, who then call ATF and they come and decide if you have violated the regs.The issue is "Murphy". If you want to show your firearm in public, at ranges, shoots, shows or wherever, or you have a house fire or a car wreck or a medical emergency, or a disgruntled neighbor, any of a number of unforeseeable events, and the cops show up, or the EMTs show up or the fire department shows up and for some reason they want to know about the firearm. That's how people get in trouble. That's why you should know and comply with the regs. Let your conscience be your guide.

As for what stocks are available, that is easy to find out on google.........

Edited July 10, 2017 by Black River Militaria CII

[dokkerdam]

that's what I was looking for, thanks.

I know it's not your end of things on the other questions and I've seen stocks and adapter plates on the internet but i'm looking for advice about the feasibility of doing this to the aluminum frame and which stocks fit on which adapters . I haven't seen any detail like that on any of the stocks or adapter plates listed other than what they are. I think that older 1928 stocks are identical to new manufacture as somewhere there was a comment about that possibility but i'd love to hear from a Thompson specialist who can say for sure. Remember that lots of changes were made to receivers, frames and insides when the firearm was reissued to prevent people from creating fully automatic weapons and I don't know where those changes stopped.

thanks again,

dokkerdam

[Bill DeShivs]

There should be no problem attaching the hardware to an aluminum receiver, as long as the attaching points are thick enough to adequately support the attaching screws.

[dokkerdam]

Thanks for the comment.

 

i'm starting to see a gouging on the feed ramp of the aluminum receiver where the cartridges actually scrape on their way into the chamber. I've put about 400 rounds through the Kahr Thompson and I think given what i'm seeing that there must be some approximate number of rounds that the receiver can tolerate before feeding becomes an issue. i'm going to contact Kahr this week and send them photos of the problem. Anyone with actual experience with aluminum receivers would be appreciated but please don't just write 'I wouldn't have bought one' as that doesn't help me.

 

dokkerdam

[Bill DeShivs]

Aluminum receivers work very well in pistols.

They hold up quite well-not as well as steel, but well.

I see no reason it wouldn't work as well on a semi auto rifle/pistol.