I have tried pretty much everything I have seen online but the electrical cleaning.
Any suggestions would be greatly appreciated.
Help Please!!!!
I see you've already got about four pages of suggestions for various chemical treatments intended for heavily fouled bores. If you're willing to set some old wives' tales aside, I have a suggestion for you:
Scrub the hell out of the bore with medium steel wool wound around a worn out bore brush until it is tight enough in the bore that you need a little help from your other hand to run it up and down the bore. It will do a good job for everything not laying in the bottom of a pit or the inside corners of the rifling grooves that are out of reach of the steel wool. Then try your chemical cleaners of choice after that. Or soak your steel wool with your chemical cleaner of choice while scrubbing away.
Hundreds of thousands of shooters are poised to leap to their keyboards to inform you that using steel wool in your bore is sacrilege: doing this will guarantee you have just damaged/ruined your barrel. That has been gospel truth passed on to the masses for generations. Two of my childhood gods, George Nonte and Jack O'Connor, wrote about this dangerous transgression. That's where I first heard this tidbit of knowledge.
Meanwhile, McGowan, Montana Rifle Company and more than a few other custom barrel businesses "hand lap" their barrels with that exact same steel wool. And I've watched some of them doing it, standing in their shops.
As I've mentioned here on Gunputz elsewhere, I spent most of last year getting a barrel shop that had gone up on the rocks in operation again. One day after work was over and the crew had gone home, just for poops and giggles, I pinned a barrel blank that had been rejected for flaws (button slipped and rifling ran parallel with bore axis for a short distance) to determine starting size.
Then I attacked the barrel with steel wool as explained above, labouring away to see how long it would take me to round off the bore edges of the rifling grooves and/or increase the bore size enough to run the next size up pin through the bore.
After about an hour, while the borescope showed the rifling edges were still sharp and the barrel still wouldn't accept the next size up pin gauge, about all I had was an extremely shiny bore with practically every single reamer mark removed, and a very pretty but still below standards rifle barrel blank. So I shut 'er down and went to pull a wobbly pop out of the fridge while I pondered on how much of the rest of my "everybody knows" knowledge wouldn't survive a test.
However you clean your bore, if you're unsatisfied with the bore condition afterwards, you can do actual hand lapping. Cast a pure lead lap and then work on cleaning up the bore surface of pitting, depending on how deep it is, and calculating when continuing to lap will transition from making things better to starting to make things worse.
I have only lead lapped a few barrels; each one took me about one Saturday of leisurely slow paced work - lots of pauses for measurements, pinning, pouring a new lap, etc. As is often pointed out with similar work: it's a hell of a lot easier to cut something than it is to add it back afterwards. A barrel shop pro/gunsmith could probably do the same job in two or three hours; doing my own work I'm in no hurry and it is my barrel, not somebody else's.
This is where the bullet casters are happy campers: up to a point they can lap to their heart's desire, and then adjust cast bullet size to get the fit they want with that barrel.