I picked up a berrel where the feed ramp portion has been cut out by angry beavers and I would like to know is this salvagable, and how can I fix it?  Pic's and or links would be helpful.

slap a little jb weld in that there "berrel", Jethro.

That is not what I was looking for, and that would not work for long.  I was thinking of TIG welding material back into the spot and milling new feed ramps.  What is a barrel extension and would that work?

Forget it.  The barrel is scrap.

Replacing a barrel extension is not easy, and would likely cost more to have it done by a smith than it would take to buy a new in spec barrel.

I plan on replacing the the barrel extension so the cost is my labor I just need to know how to do it.  What tools I might need, and what tips someone can give me to help in the process.  I'am my gunsmith I haven't ever had the need to do this and I like the prospect of the challenge.  So, please give me good info on this, it would be much appreciated.

Can you post a picture of how bad this extension actually is?  

I would clean it up before I would replace it, but that is just me.  The worst that happens is that it doesn't work....

I would not weld on it, as there is little extra metal here between the feedramps and the locking lugs.  Not much of a heat sink.

Since you have a mill, how about cutting away the feedramp and JB welding in a replacement block and cutting on that?

EDIT:  A very light touch with a TIG torch to tack it in place instead of JB compound sounds better.  When I talk to welders, they are talking 125 amps for full thickness welds....  Most are not into gunsmith welding.

depending on how bad it is and if its a standard ramp i would get a M4 cut upper and then try and do your best to match the buggered ramp up to the extended.

and the way i understood it is the ext is threaded right handed but tight as all hell, think they said something like 160 foot pounds.
i would defently try and make the ramp work before i tried to get the ext off.

I had thought of cleaning up the angry beaver grinding that had been done to it, it is in a kind of Triangle shape with the top of the triangle pointing down the barrel.  I then was going to frind another piece of barrel and cut a tight fitting piece that would fit in the ground portion.  Then I was going to use about 50amps with the TIG so I can control what I'm doing and and not burn throung to the part where the bolt rotates.  All the locking lugs are present they didn't grind any of those out just the feed ramps.  
160 ft/LBS I can do that, I was thinking of heating the Extension with MAP gas and heat sinking the barrel and then take it off.  I would be better for easier for me to remove the extension and put on another then to do all the grinding and welding.

Quoted: I had thought of cleaning up the angry beaver grinding that had been done to it, it is in a kind of Triangle shape with the top of the triangle pointing down the barrel.  I then was going to frind another piece of barrel and cut a tight fitting piece that would fit in the ground portion.  Then I was going to use about 50amps with the TIG so I can control what I'm doing and and not burn throung to the part where the bolt rotates.  All the locking lugs are present they didn't grind any of those out just the feed ramps.   160 ft/LBS I can do that, I was thinking of heating the Extension with MAP gas and heat sinking the barrel and then take it off.  I would be better for easier for me to remove the extension and put on another then to do all the grinding and welding.

I'm not so sure 50 amps is enough, but it might be.  I know just trying to spot weld over pins on FHs, I was having issues with 80 amps and too little heat.  I'm not a pro welder, though, but I get to play at work every now and then and at home on even rarer occasions.

Weld build up and remachine is a common parctice in other industries, so why not here?  If done with care, I could see you being successful.

I use a foot petal on the TIG so I can bump it up if I need to, I was planning on useing layered small passes until I filled it, and using half of a thick brass pipe to fit down in the rotation area as the heat sink.  This should also, keep the burn through from happening.  I have done some Aluminum TIG welding, so I figured if I went slow and took my time I get it done right.  But I would still like to get more info on replacing the barrel extension.

Lastly this a 1:12 twist CAR barrel that is why I would like to salvage it if possible.

Quoted: I use a foot petal on the TIG so I can bump it up if I need to, I was planning on useing layered small passes until I filled it, and using half of a thick brass pipe to fit down in the rotation area as the heat sink.  This should also, keep the burn through from happening.  I have done some Aluminum TIG welding, so I figured if I went slow and took my time I get it done right.  But I would still like to get more info on replacing the barrel extension. Lastly this a 1:12 twist CAR barrel that is why I would like to salvage it if possible.

Sounds like you have a good plan, there.  Good luck.