You are, however, absolutely wrong about the “cutting torch” part.
The highest pressure, therefore highest escape velocity at the BC gap will happen the exact same regardless of barrel length - the max pressure happens typically with the bullet base slightly one side or the other of the BC gap.
Flash will escape the BC gap as long as the bore is under pressure, aka the entire time the bullet is in the bore. If the bullet stalls, the flash through the gap will look exactly as it did if the bullet did not stall. There would not be some magical “reserve” of flame that suddenly realized it could not exit the muzzle, then ran backwards to rush out the BC gap. Study up on what pressure means, you’re way off base for actual science.
In a literal and physical sense, THERE IS NO LENGTH IN WHICH A REVOLVER BARREL CAN BE LONG ENOUGH TO FIRE SLOWER THAN A SHORTER BARREL DUE TO THE BC GAP LOSSES. Even a sealed breech firearm can be made with a barrel long enough to stall a bullet, the BC gap just helps that happen in a shorter length - but it is NOT wholly dependent upon the gap.
All you really need to understand to be able to comprehend this:
1) there must be positive pressure to be vented through the gap.
2) positive pressure represents an accelerating force on the bullet.
3) the longer a bullet is exposed to an accelerating force, the faster it will be traveling.
This is high school physics stuff, fellas.
We shoot these cartridges in 20” barrels all of the time. Even paltry little rounds like 38spcl, 32 short, 22LR... If the ~9% loss due to a 6thou BC gap were enough to cause a stall, then the 20” of barrel drag would be enough too. If you have any muzzle flash or black smoke you have additional potential for pressure (fuel to be burned), even if you didn’t have flash or smoke, you would then remain to have positive pressure for a lot of barrel inches. Only when the combustion is complete AND the pressure is fully expanded to just above a net balance with atmosphere, ONLY then will the bullet stall. BC gap or not.
I believe the Dan Wesson & lots of Smiths came out with 10"+ barrels didn't they?
I have a few Smiths in 8 3/8" barrels in 44 mag & 357 mag which I -heard- had something to do with
competition barrel length or something, I may be wrong.
The super long barrels 10"+ should really light up the cylinder gap shouldn't they?
And loose more power than they are worth producing?
Reminds me of the old western revolver with a rifle stock & long barrel, I wonder
how their performance was.
I would really have to study for reloading a modern super long barrel.
I remember Dan Wesson dominated long range at one time but wonder what length
barrel & model it was.
My son says he would buy one if we could find out some creditable info.