I have been trying to get the carbon off the end of my Sig 365 XL Spectre Comp barrel for days.  I tried the Vinegar and Baking soda trick several times, and left in the solution for a few hours.

Here's a look: https://imgur.com/a/vZyJamy

Whats the best course?

Ultrasonic bath with simple green for a hour hours would probably do the trick.

" />

Are you guys being serious?

Ultrasonic or Simple Green won't take off the TiN coating. Why would you think that it wouldn't work?

Just because I dont have access to an ultrasonic bath.  What about just soaking in Simple Green overnight?

IS there anything stronger than Hoppes 9?  Ive never used BreakFree or CLP.

This shit is hardcore - never seen anything like it but never had a barrel like this.

Seriously only <100 rounds of good Blazer, too.

Where in TN are you located? I've got a really nice dual frequency commercial Ultrasonic cleaner if you're close enough to drop if off and we can let it soak. It's really the vibration of the cleaner fluid on the surface of the item to be cleaned that should remove stubborn deposits, not just the soak.

As to as stuff being stronger than Hoppes No 9, I'm sure there is but I wouldn't know what it could do to that coating on your barrel. A lot of bore cleaners are strong as heck but they are strong solvents.

I have this same gun.  Cleaning the barrel was difficult for me but I just tried Simple Green solution (just the all purpose kind, not the industrial) in a simple dental appliance ultrasonic cleaner for 16 minutes and it totally removed the carbon buildup from the end of the barrel.

Here is the before and after pictures:

https://www.dropbox.com/t/wjlNpKugbcNYJMJH

https://www.dropbox.com/t/PjSzjDo4dchMA2uW

I appreciate the advice from this thread.  I just joined because i was so thrilled this simple technique worked to CLEAN MY TITANIUM NITRIDE BARREL.

My ultrasonic cleaner was nothing fancy.  I think I got it on amazon.  Its a Magnasonic MGUC500.  I think it was only like $30-40 and I have used it to clean dental appliances but never a gun barrel.

It's been a while but I read online that regular Simple Green can be corrosive to aluminum parts, so I got some aviation simple green. Wives tail? Could be.

ETA:
From https://simplegreen.com/faqs/

Is it safe to use Simple Green All-Purpose Cleaner on aluminum?
When used with caution and according to the instructions, Simple Green All-Purpose Cleaner has been safely and successfully used to clean aluminum. Simple Green All-Purpose Cleaner, Crystal Simple Green Industrial Cleaner & Degreaser, and Simple Green Pressure Washer Concentrates have been used on aircraft, automotive, industrial and consumer aluminum items for over 20 years. However, caution and common sense must be used: aluminum is a soft metal that easily corrodes with unprotected exposure to water. The aqueous-base and alkalinity of Simple Green All-Purpose Cleaner can accelerate the corrosion process.

Therefore, contact times for unprotected or unpainted aluminum surfaces should be kept as brief as the job will allow - never for more than 10 minutes. Large cleaning jobs should be conducted in smaller-area stages to achieve lower contact time. Rinsing after cleaning should always be extremely thorough - paying special attention to flush out cracks and crevices to remove all Simple Green product residues. Unfinished, uncoated or unpainted aluminum cleaned with Simple Green products should receive some sort of protectant after cleaning to prevent oxidation.

Simple Green has also developed break-through water based cleaners that are safe for use on metals, plastics, rubber and high tech alloys. Extreme Simple Green Aircraft & Precision Cleaner and Simple Green Pro HD are available on both the industrial and retail markets, respectively. These products were initially developed for the aircraft industry and extensive testing shows that they are safe and effective on a variety of metals and other sensitive surfaces even in the most extreme circumstances.

You probably need a carbon cleaner. Hoppes is a pretty weak general cleaner. Carb cleaner or a similar gun specific product is worth a try. If I have bad carbon I try to keep it wet for a while then scrub it with a brush and repeat. It would be pretty easy with a barrel to just wet a patch and stand the barrel up on it and let it sit.

Good luck, carbon can be a pain. Maybe a light wipe down before hand might help.