Got an older gun and appears to have been fired and not cleaed. The outside was not bad got her clean. I am a newbie to blackpowder but I know a little bit. The nipple and cap area were fairly easy and I got the rust off. However inside the barrel has rust can see it at the muzzle end. So what do I do? Whats the best way to get the rust out.

Also how accurate will it be, How would I know if she is bad off or not before I blow my face off. It does seem to be surfac rust but it sat for about 7 years after being fired and never cleaned?/

It is probably a total loss as far as the bore is concerned.  Probababy will tear the patch badly when ramming home the ball or it could jam itself permanently when you first try to load it.  Find yourself a replacement barrel in your local classified ads or on Gun Broker.  Im not sure if Ebay still allows such a subversive item as a blackpowder muzzle loading barrel on their site.

A few things to look at,  how old is it?  What manufacture is it?  How bad is the bore?

I have seen barrels restored to shootable condition with a lot of time, work, and a few green, grey and white scotch bright pads.  

If it is newer, (as in the last 20 years) chances are you can get a replacement barrel,  will be easy if it is a hook breech plug that you can get a drop in from the manufacture or even Green River.

If it is an antique,  you may have some luck with having a barrel maker take a look at it to see if it can be re bored to the next caliber up.    (I have also seen this done)  If not this same barrel maker can make you something in the same size and profile as what you have.

It is less than 20 years but I hate to buy another one. I think I will take it to a gunsmith to see what they say then go from there!!

I think its Green Mountain not Green River. Id try this electrolysis method first followed by a bore brush and some bore butter to keep the rust off the metal.

Great link thanks

Yea,  thats what I was thinking of  Green River is cutlery

Zack,

Thanks for the link.  I have a couple of old black powder rifles that belonged to a hunting buddy of mine.  He died in a car crash several years ago.  He didn't take real good care of them and I played around with cleaning them up a while back, but gave up and just oiled them up real well to slow down the rusting.