According to whom?
Think about it, permanent or not, cutting the loading port does not make it a cartridge firearm. It's still a percussion gun and will function as a percussion gun, albeit with a large capping port. Physically installing the cylinder is what makes it a cartridge firearm and that is not permanent. YOU do that as an individual, which is perfectly legal, unless you're doing it as a money making endeavor.
The license is irrelevant in this context. If cutting the loading port made it a modern firearm, they wouldn't be able to send it directly back to you AS a percussion gun. It would have to be transferred through an FFL. If it's a Howell or a Millington and the conversion is permanent, then it would have to be transferred as a modern firearm. Just as the Howell was I bought last year. Because the conversion ring is permanently attached to the frame and there is no percussion cylinder. Not because it has a loading port.
Sir
You are misconstruing and or misunderstanding the issue.
Once a loading port is cut on a percussion frame, According to the BATF you have manufactured a PMF.
it no longer matters which cylinder you put on the frame.
The defining issue is “permanently modifying” what was previously considered a nonfirearm.
You are apparrently unaware that the BATF shut down several airsoft gun manufacturors because one
BATF technician was able to put real parts in different airsoft guns and make them fire one cartridge.
According the the BATF, “the frame is the firearm”
This is exactly the same as an “unfinished” 80 percent 1911 frame.
As long as the frame does not have certain holes or rails cut, it is a chunk of metal.
Once a person drills the holes and cuts the rails, it is now legally a firearm.
In this case a PMF.
It does not require a serial number until it goes up for sale or thru the hands of An FFL holder.
Cutting a loading port in a percussion revolver is the same thing to the BATF.
As far as I know at this time, The BATF and/or Courts have not produced a specific ruling regarding percusion to cartridge conversions.
Until someone request a letter or ruling, or the BATF decides to chase someone down, the entire issue
Is a dangerous grey area.
It does not matter what or how “some” gunsmiths shipped modified frames - it is an undecided area that
Has not yet been clearly decided either by the BATF or the courts.
Apparently Howells has made a similar statement:
“ This conversion cylinder is classified as a “part” by the BATF, and No FFL is required to purchase or ship this product. Once the port has been cut in the frame, it is considered a permanent modification of the revolver and is therefore now classified as a “FIREARM,” and all Federal Regulations shall apply.”
Found here
https://howellarms.com/product/uberti-steel-1858-army-45-lc-6-round-gated-conversion-kit/And, frankly, unless you are an officer of the court with experience in BATF issues, in actual court cases, your opinion holds no water. I do not mean to be rude, but its rather like someone trying to argue that a cop cant write you a speeding ticket if he is using LIDAR.
Bottom line - to quote Rooster Cogburn “you do what you think best, Ned”.
I will follow my own (and the other guys) advice and err on the side of not provoking the BATF in any way.