You used way too much JB, shouldn't need more than 10 or so patches, followed by regular cleaning processes.
I don't think I've ever used more than 10 JB patches each on my Mosins when first acquired, and those have always needed the most initial attention of any rifles I own.
As noted, JB will NEVER come out anything but black.
And with it being an abrasive, even a mild one, you're scouring away the bore surface if you use it for a couple hours.
You may possibly have rounded off your lands somewhat.
Run your regular cleaning process now, try some factory ammo through the gun, see how it shoots.
Never judge a gun by jumping into it cold with handloads as a benchmark.
Use a known quality commercial load or two.
And understand lead bullets will just about always be dirtier than jacketed.
I'd suggest you stop obsessing over the bore & just get down to shooting the gun.
Denis