New Star Firestar -- preemptively polish the chamber?

[Aguila Blanca]

If the chamber has actual rings in it, polishing is going to make shiny rings. If they are there and if they cause problems, rather than using a rotary tool to fluff and buff the rings, I'd rather take a length of wood dowel, wrap some crocus cloth around it, and gently run it in and out of the chamber to knock down the rings.

If they're really bad, I might start with fine-grade emery cloth, and then move on to crocus cloth.

 

[Metric]

Thank you everyone for all of the ideas and feedback.

Unfortunately, the problem is no longer theoretical. I tested today with three mags of geco 115gr fmj. First mag was fine. Second mag had a FTE on the 5th shot. At this point, I knew more were likely to come, so I switched from a 16lb recoil spring to a 22lb spring, just to see what would happen. Third mag encountered another FTE on the 3rd shot.

I guess the gun was purchased in the mid-1990's, the owner fired a few boxes of ammo and couldn't get it to work, and it then became ballast for his gun safe for the next 25 years, until now. Would explain the overall nice condition of the bluing.

Okay, so I intend this to be the first thread on the entire internet where a real fix for this issue is described. Or I go down in flames.

Here's what the FTE's looked like:

First one:

Second one:

The brass on these FTE cartridges have lines that definitely look like "rings."

Inside the chamber, I can definitely see areas in the forward half of the chamber that are more irregular than others, and which accumulated more residue from the first few mags.

When the fired cases are put back into the chamber, they do seem to have quite a lot of friction when they are fully forward. Not sure how unusual this is, though.

I like the idea of kind of "lapping" the chamber with an abrasive of some kind, before I use a rotary tool. I have some 1200+ grit sandpaper as well as some 3000 grit diamond paste. Thinking about using one or more of these forward and back, and then following up with a dremel and flitz.

Any further advice or observations are appreciated. BTW, the extractor seems to be working perfectly well -- tight but not too tight.

 

[Metric]

On closer inspection, I can see those rings very well in the chamber, with a very bright light. And yowsa, they're serious. I think most of them are grooves rather than mountains, but I could be mistaken.

In any case, I'll see what I can do to the friction coefficient in there.

 

[HiBC]

Well...Maybe.
Something about the double feed and partial extraction makes me wonder.

I'd think a true rough chamber fte would pull the extractor over the rim.

I'd think you would have the case full depth in the chamber.

Somethings happen quicker than you can see.

What if your extractor is doing a nice job of holding the cartridge brass on the bolt face.

I don't know what sort of ejector you have,but what if its failure to eject?

Maybe the brass is riding the slide and getting shoved back into the chamber.

Its not an uncommon thing.

Beware tunnel vision. A guy could sandpaper a chamber over an ejector.
I think I'd leave the chamber alone for now. Or just clean it with a bore brush and some BoreTec or Wipe-Out.Later,If I just could not sleep without doing something to the chamber,

If twas me. I'd figure embedding some of your 3000 grit diamond in the brass case would cut slow. Very low risk. 3000 grit should have a rock size of .0003 or .0004. It won't cut much clearance/oversize from the expanded brass. Sandpaper lacks form. It can wallow out geometry. The brass will stay true to your chamber,and just float the high spots off.

Shooting 10 or 20 or even 30 of those won;t hurt anything. Pay attention to progress.

But only make one change at a time,or you don't know what worked.

Myself,I'd study the ejector. You might need a firmer grip. Or zippier ammo. Or the softer spring.

Whats Geco?Some little lizard? Try some 124 gr white box or fiocchi or good SD ammo. A little more slide velocity might fix you right up.

I'd lose the 22lb spring. I don't know your gun,but a slide bashing its way forward with too much force hammers the gun.

The double feed happened with the 22 lb spring. It takes time for a mag spring to lift the ammo up to feed. A 22 lb spring does not give your mag time to feed.

Careful about fixing what ain't broke.

I'll grant,seeing rings in the chamber is discouraging. But your cartridge brass is not looking like Acme threads. Brass can span over some defects. Like a bridge over the valley. Don't even think about polishing out the valleys. You will make scrap. The valleys don't touch the brass. Its the peaks that may bite into the brass. Lap off 25 % of the defect (for example) and you lose the "barbs".
I'd seriously put your Dremel in a drawer and keep it away from your chamber.Using it,you will make it easier for the brass to deform rather than bridge.
You are already missing steel. Dremels do not put steel back on. they cut more steel out.
Good luck!

 

[Metric]

Interesting ejector hypothesis -- here are a couple counter-points.

1) I've seen references to other people replacing the ejector before, with no effect.

2) If the ejector were bumping the cases back into the chamber, I would expect to see many more jams in which the case didn't perfectly find the chamber again, getting hung up in an awkward position in the port. I didn't see any like this, and I can't find anyone else complaining about that kind of jam, either.

I will back off on the spring weight next time. But I might not go all the way back to 16lb, since there was apparently plenty of momentum to cycle the slide even at 22lb -- and this is even with the added chamber friction, and using 115gr range ammo!

Yeah, those rings inside the chamber are a bummer. There isn't much to lose, so I'll see what I can do. In handgun calibers, I haven't been able to find many people talking about how a chamber polish ruined a barrel. But maybe there are other reasons for that. If reliability goes straight to hell after my efforts, I'll mention it here.

 

[HiBC]

The brass on these FTE cartridges have lines that definitely look like "rings."

Or they could be chamber mouth scuffing..

Are they + or - deformity? If the brass expand outward into the "ring" and gets sheared off,thats one thing. If its a scuff or impression into the surface,its another.

But,its your gun. I did my best.

Figure I have learned many of my own lessons the hard way.I know them well.

I would not want to rob you of a growth experience.

you know,Edison discovered maybe 10,000 times,"That one ain't gonna work"
There was an 18th century British poet,William Blake.Pretty smart guy.He nvented printing via etched copper plates.

There is a portion of his work "Proverbs from Hell." Picture these as bathroom graffiti. No insult or disrespect intended,this applies to me,too.

"If a fool will persist in his folly,he will become wise"

I don't suppose I could have talked Kyle Rittenhouse out of going to Kenosha. At least not then. I bet now,he;d rather go North for some Pike fishing,eh?

might be,some day,if you could figure out the magazine end of things,a 357 SIG reamer might clean that chamber some....(just kidding!)

 

[Metric]

Thank you for the guidance HiBC, and I absolve you of any and all responsibility for my wild-eyed dremel madness. Angels apparently fear to tread this territory, so that's where I come in. (cue dremel revving sound)

Actually, the deed is already done -- or at least the first step of it. I tried a few things. First was just a deep clean, just to see the full extent of the problem (which is indeed pretty bad).

I tried a few techniques for "back and forth lapping." One was to wrap a bore brush in 0000 steel wool and manually lap with it. Not sure it accomplished much, but maybe. I also tried some 400 grit polish compound on a q-tip over the worst problem areas, and eventually tried coating a fired cartridge case in the stuff, and repeatedly chambering it. Pretty sure the effect was minimal -- I didn't do these for long.

Eventually, I broke out the dremel tool and attached an old felt wheel with some residual 3000-grit diamond paste in it. This rapidly shined things up, and while I can still see many of the worst rings, I have reduced the overall impression that the chamber was cut with a reamer someone found at the bottom of a Spanish lake.

So it's ready to test again, next time I have a window to drive out of town. I'm fully prepared to encounter failure at this point. It's conceivable that I haven't gone far enough, or that I have gone too far already. We'll see.

I'm already keeping an eye out for a new barrel, in case of irreversible failure. But I do think there is a reasonable chance for success. The chamber just looks far less frictiony, and the actual fired cases have a more "tight but smooth" feel when fully inserted back into the chamber.

I guess I'll find out soon.

 

[Metric]

Was able to test again today, over lunch. Results are encouraging, but I'm not completely to the finish line, yet.

I fired 11 full mags (7-rounds each), plus a couple of "+1" extras.

I had two FTE, one on mag #4, and one on mag #10. The first FTE was with geco 115, the second FTE was with federal american eagle 115. I also fired two mags of underwood 90gr +p xtreme defenders, without issue.

The brass looks substantially cleaner this time, and the biggest "problem spots" from the first test, where I did the most polishing in the chamber, are no longer the biggest problem spots on the brass -- this is probably the most encouraging aspect of the test. There was no sign of bulging, pregnant brass -- I had taken it pretty easy on that first polish. But I can still see some rings -- areas of unusually high friction (the chamber was really filled with them before).

In any case, 2 out of 11 mags seems a lot better than 2 out of 3 mags (actually less than 3 -- I didn't finish the mags that encountered a FTE during the first test).

I haven't cleaned and examined the chamber yet, but I know pretty well what to expect, based on the brass.

 

[Metric]

Just finished the second round of polishing.

Encouraged by the early sense of "moving in the right direction," I got more aggressive the second time through, using fresh 3000-grit diamond paste, and a tighter-fitting felt tip. It should either be "fixed" now, or else I've gone too far. I doubt it will be "borderline enough" where I get a FTE every 150 rounds. But I can also feel the fired brass from the first test is a bit less tight in the chamber than it felt before, so it's possible I have committed a Bubba.

If so, I'll look for a new barrel, and hope to god it isn't buggered from the factory. But first a test.

 

[hounddawg]

the thread got me curious so I did a quick Google. Looks like polishing is a pretty common practice. Might try Flitz or Iosso on a felt Dremel tool. I like to use Iosso when cleaning my rifles

https://www.google.com/search?q=pol...B6xaSAQoxOC42LjEuMC4xmAEAoAEB&sclient=gws-wiz

 

[44 AMP]

I've never used GECO ammunition, so I won't comment on it. But I have had a few cases marked GECO or GECO-BAT show up in my brass supply. They've always been crap. And I toss them when I find them.