TurtlePhish said:
Be careful. You might need to register a flare gun as a DD if you own one.
While it could be a problem, I would think the same logic would ultimately apply as has been used by the SCOTUS before.
For example in the Thompson case they said if there was a legal possible use for the short barrels like when assembling a pistol, then it could not be presumed their purpose was to assemble an unregistered short barreled long gun by installing them on stocked guns they could fit on.
So just possession of a short barrel and a stocked firearm that could use it was not proof that someone possessed a short barreled rifle, as long as there was a pistol or legal pistol configuration that could make use of the short barrel.
If the person has a legal use for the item, ie they have a 12 gauge shotgun that is not a flare launcher, then a 12 gauge insert could not be presumed for use in a 12 gauge flare gun just because they own a 12 gauge flare gun. Unless there is additional evidence the person used or intended to use it in the flare gun and not the shotgun.
This is not legal advice but simply how it should be interpreted based on prior cases.
Now if the insert is in a caliber obviously intended for use in the flare gun, like say a 38mm-12 gauge conversion, then clearly its purpose is not for use in a legal firearm, but in a 38mm bore diameter launcher, and the resulting firearm will still have a bore over .50 and so the ATF gets their discretion to consider it a Destructive Device.
Or if the person does not own a 12 gauge shotgun but does own a 12 gauge flare launcher then an insert for a 12 gauge in their possession has no legal use (better not sell your shotgun and forget you have them) and may be presumed for illegal purposes even absent additional evidence.
If a person is walking around or traveling with a 12 gauge insert and a 12 gauge flare pistol, even if they have a 12 gauge shotgun at home it may be reasonable to assume their intention was not to legally use it with the shotgun at home, but illegally with the flare pistol that is present. (A jury would get to make that call.)
Many of the stocked flare guns are also well below the minimum 16-18 inch barrel requirement, or 26" overall length. So if intended or used with actual ammo they could be considered unregistered short barreled shotguns/rifles as well when possessed or used with an insert.
While a flare launcher pistol with an unrifled insert would also be an AOW because it would be a smoothbore pistol.
However if the final characteristics do not fit an NFA item, and the overall bore diameter is under .50, then it is just creating a title 1 firearm which anyone can legally do.
So a flare launcher pistol possessed with a rifled insert that shot a projectile below .50 bore diameter would presumably be legal, as the combination would only result in a title 1 rifled pistol, which most unprohibited persons can legally create.
I still wouldn't play that close to the edge, as those who enforce the law are not lawyers and you may still end up in court trying to convince a jury, a jury that are themselves not firearm experts and are confused trying to understand it all.
