Had a co-worker give me a 54 Cal T/C Renegade yesterday and while the exterior is really not bad - the barrel has 'some' rust inside. I suspect it was probably fired and not cleaned and put away. It's not a heavy coating but more like a surface rust that is not too heavily dug into the metal. I can still see the rifling but it is going to take some work to get it shootable again. Been doing a lot of research and the consensus seems to be a several day soak with Kroil in the barrel then a lapping with green Scotchbrite impregnated with either JP Paste or water soluble valve lapping compound. Just wondering if anyone has a better idea or maybe something that will work better on the rust. Anyway throw out your ideas or what YOU have done to give me some options. Thanks!

A tight patch some polishing compound and a lot of elbow grease will do the trick.
I had a 50cal.Hawkin years back and I had to remove the end of the Barrel to clean it out. If You go that route please buy the propper tool so you dont mar the end of the barrel.

As stated above tight patch, pull the Breech plug if needed. Track of the wolf should have a tool.

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Front sight and squeeze

Tight patch wrapped around a bore brush or jag with kroil will work wonders if the rust isn't bad. And get some rem clean which has a pumice type abrasive in it. Shake the heck out of the container till you hear the ball bearing rattle and apply to the tight patch. Best if you take the barrel out of the stock and sandwich it between two pieces of wood in a vise. Buddy had a trapdoor springfield that sat for years in a basement. made up a long cleaning rod from two shotgun rods, 45 caliber jag and tight patch. Took the barreled action out of the stock and sandwiched it between two 2x4" that I drilled a hole through lengthwise for extra clamping power. Took a couple of hours and a pile of patches and bore brushes but when done you wouldn't believe how nice that barrel looked. Frank

Hopes and a good brush for the chamber, make sure the brush is not the press on kind, it could pull loose and stick in the chamber. When the chamber is as clean as you can get it load the gun with a moderate amount of powder, and equal amount of corn meal, a patch with a drop of motor oil and a round ball. Shoot and repeat until you get tired of having fun. It will polish the barrel and leave no buildup between shots. Clean and oil when done.

Update on my Renegade project:
Well I must have done something right because this Renegade is SCARY accurate! The first shot is the one in the red from 50 yards kneeling. 2nd is the one about 2" to the right and was my fault. #3 was the one above the red (after a sight adjustment) and # 4 was the one at the one at the top after another click 'up' on the rear sight. Decided to drop down a click and set the cup at 100 yards and you see the result - It shoots incredibly flat and about the same at 100 as it does at 50. I think it lives!

Reading this thread, it sounds exactly like a thread I started in another forum a few months ago. TC Renegade in .50 Cal. Seller advertised as rust free, but it has rust in the barrel. I don’t remember exactly what I used, but I soaked some steel wool in something (wish I could remember what) and it did nothing to the rust. So, I’m wondering if you got the rust out and if so, what did you use? I can also see the rifling.

I capped the nipple and filled the barrel with Hoppes and let it soak for a week. then I clamped the barrel in a vise (heaver leather pads!) and scrubbed it with a standard bronze bore brush. I was surprised at how much of the rust came out. After I got what I figured was all the rust out I made a tight fitting cloth 'swab' and applied water soluble valve lapping compound to it and lapped the barrel until it started to feel smooth and then stopped. I didn't want to go too far with the lapping compound as I did not want to remove too much metal but I think it would have taken a lot more passes than what I did (maybe 20 passes) After that I used the bronze broush and Hoppes to get the compound out then a finish with Hopps and a 20 ga shotgun bore mop. Shooting it yesterday really helped as it got easier to load after each shot.

Thank you for the info. I’ll give it a try.