A friend brought me his 100 and said it wouldnt cycle. Test fired it and had to drive spent round out with a cleaning rod. I scrubbed the chamber real well. The extractor is nearly ripping the rim off.

Im looking for some way to polish this out. Here is a pic of the brass

TLB2: pic is not too clear of fired brass. Take the guts off the barreled receiver, use a penlight to examine the chamber. Take more pictures of the fired case - if the chamber is rough - the fired case should show an "orange peel" pattern. You can try to polish the chamber walls with 400 sandpaper but don't touch the shoulder or chamber neck. Take it to a reliable gunsmith if you are not comfortable doing the above. M100 chambers are like M742 Remington chambers - no one cleans them and they get pitted and the extractor tries to do it's job and pulls the rim off the fired case which has expanded into the rough chamber upon firing.. Remington makes a chamber brush to scrub the chamber and it should work on the M100. Is the owner shooting FRESH factory loads or hot reloads or old ammo that was subject to high temperature in a hot car? That could be the problem. If not - you have a parts gun!Good luck with it, Mel

The shiny spot at the end of the neck is where it seems to be sticking. You should be able to see a shiny ring on the brass

Im shooting new factory hornady 150


I cleaned the chamber with a .45 cal brush wrapped with lubed steel wool spun slowly with a drill

That won't do it..

Do what melchung advised above.. Only way to polish those chambers properly is to completely disassemble the rifle so as to be able to get at that chamber - and the use of 400 grit paper is what I use also..

WOW! I used 1200 grit and was a little concerned about being too aggressive. Maybe I spent unnecessary money on a new barrel.

I've used 1200 before - in fact, I've used 2000 a couple times.. But that was when I was polishing a shotgun barrel in prep for hot bluing.. The customer wanted a shine he could see his face in..

But on a chamber, 500 is about as fine as I'll ever go. 400 will polish any S/A chamber in order to give proper function..

320 is considered industry standard. 400 is extra fine and considered by many as so fine it's hard for the brass to grip and will cause excessive bolt thrust. I call BS. The excess bolt thrust thing is a myth. The brass is only a bladder like an inner tube. Having the chamber super smooth hurts nothing. Polish it like chrome if you want. It hurts nothing. I think 400 is perfect. Keep in mind that with 400 the brass will leave marks in the chamber. It will look all kinds of scratched up even with pristine brass. After a few hundred rounds the marks will start to blend together and not look so bad.

Under normal pressure brass springs back .001" so it should never get really stuck. Excessive pressure will stretch things out beyond what the brass will spring back and that when they get really stuck. Ripping the rim off stuck. This is why I really dislike cutting the shank section out of a barrel for the purpose of saving weight. A high pressure round needs that bulk over the chamber to contain the pressure. Another factor in sticky bolt opening can be if the lower ramp has been cut on to aid feeding long rounds. That will allow that lug abutment to flex and that will allow the brass to expand lengthwise causing a sticky bolt opening.

I used some finer than 600 and then I thought about it. In hand fitting parts 400 grit is the last step before true polishing. Removes almost no metal without really trying and gunk contaminating a chamber is considerably softer. Actually broken down 320 silicon carbide works best for me for cleaning up a chamber. When the bench is clean 400 does it.

For semiautos like the 100 extraction force is not great. Consider the area of the case that can contact the chamber, it doesn't take much gunk - carbon, surface rust, whatever - to cause problems.

Like HiredGun said in properly prepared ammo the brass springs back enough that polishing finer than 400 doesn't really add anything.

Thanks for the advice, Ill tear it down and polish with 400

You and I are on the same page of music,....

I've almost always started with 320,...and than gone progressively finer, as the spirit moved me.
If one doesn't understand the term uniform crosshatch, and surface speeds as it directly relates to the process of lapping, the wise thing to do is bring your recalcitrant chamber to someone who does.

I've got 3M Emory paper all the way out to 2000 grit,...there ARE times and places places where that comes in handy.

GTC

another 10X

GTC

All wonderfully stated...

Excellent..

Hopefully I got it polished enough. It took several times polishing with 400 grit in the neck area.

5 out of 6 fired brass will extract with my fingers. I will try to shoot it this weekend.

Thanks for the tips!

Well it didnt work still scarring the brass right at the end of the neck. I wish I had a bore scope so I could see in the chamber.

Will a chamber reamer turned by hand clean the chamber up enough to get it to extract?