[yosuthnmasa]

After pushing out my barrel, I noticed that it had some fairly deep surface scratches on it. I looked in the front trunnion and noticed that a fairly large piece of metal had been dislodged at some point in time and caused the large scratches. Inside the trunnion it still looks semi-smooth, but has a large piece of metal that has been displaced a bit. Just trying to get some suggestions on how to handle this one. If I were to get a new trunnion then I might run into some headspacing issues, because the current trunnion and barrel came as a set. But if I push it back in, it might dislodge the metal, making the trunnion a little weaker in this area. I was also thinking about taking a file and smoothing down the rough edges on the barrel. How much would a new trunnion run me?

edited for pictures: here's a shot of the barrel and the grooves cut in it from the trunnion. Also, a picture of the dislodged flat piece of metal in the trunnion.

 

[Triangle 66]

I wouldn't worry about it. Clean it up (lightly) with some fine sandpaper or a needle file and reassemble without fear.

The whole diameter of the barrel bears against the whole diameter of the trunion,with a small portion of the barrel muffed up it will still have plenty of surface area.

Actually the FUBAR-ed part may cause the barrel to fit tighter in the trunion which , as all us males know , tighter is better.

A common fix for a slightly undersized ( a few thousandths ) barrel to trunion fit, is to knurl the barrel which displaces the metal inward and outward slightly making the barrel slightly larger in diameter,athough with half of the surface contact area of the smooth barrel.

It boils down to cosmetics.

 

[Rhino_66]

Clean up that spot on the barrel with some emery cloth. You might want to see if there's a raised burr at the corner. If so, knock it down with a file. Don't take any amount of material off, just chamfer the corner down so it'll go in easier.

Like Triangle 66 said, clean up the trunnion with some emery cloth and a file. You'll be okay.

Use some anti-seize or barrel-lube when you re-press it and all will be well.

 

[hotbarrel]

I am going to agree {just to keep up my post count} lightly sand off the high spots and maby taper the end slightly. rember high spots only and just the very edge. it will be fine .. nice pics they realy help evryone to see exactly what is up

 

[yosuthnmasa]

Can you guys see the displaced piece of metal. It is not only the little edge that has move over onto the darker metal, but a bigger chunck that is part of the brighter metal just behind the jagged edge.

 

[Toten Kopf]

Can you guys see the displaced piece of metal. It is not only the little edge that has move over onto the darker metal, but a bigger chunck that is part of the brighter metal just behind the jagged edge.

I see what your talking about. Reguardless of what happened when taking the barrel out, you need to make things are right before installing it back in the trunnion. Any scratches on the trunnion should be smoothed out (no heavy grinding/filing). Next the barrel needs to be smoothed out also. The damaged area looks like it only represents about 15% - 20% of the barrel diameter so cleaning up this area and using the barrel/trunnion shouldn't be a problem. You just want to make the barrel surface as smooth and as close to diameter as the undamaged area. Also since the damaged area looks like it will be above the feed ramp you won't see the fix. Remember to work just the damaged area to maintain as much correct barrel diameter as possible. You could if you want, after smoothing the damaged area, fill it in with J-B Weld and then smooth that out to the true barrel diameter (but this really isn't necessary).

In a nutshell, smooth out the dammaged areas on both the trunnion and barrel and push that sucker in.

 

[yosuthnmasa]

I apprecaite all of the advice guys. I think I'll take a needle file and try to get the small protruding piece ground down and then maybe take some steel wool to it. The barrel shouldn't be too hard to smooth out. Don't want to take too much off though.Thanks for the advice guys!