Lead deposits in chamber of S&W Model 41

On the roof of my model 41's chamber, there is a rough patch. It's right where (I think) the tip of a bullet contacts the chamber as it feeds. This area collects some lead fouling.

I haven't really worried about it, as I'm a minimalist when it comes to cleaning any 22 but this week I had a FTF where the round got stuck halfway in. I wondered if the bullet got stuck on this rough patch.

I've tried cleaning it with some Shooter's Choice lead remover, used a bronze brush, tried some JB paste, really worked at it but there's still a rough patch there. When I run the wooden back end of a Q-tip across it, it definitely still feels rough.

Of late this gun has started to occasionally have a FTE jam. Putting a drop of oil on the first round of every magazine helps but isn't 100%. I suspect having a rough chamber isn't helping matters any.

Clearly visible in the picture below. Any suggestions?

Let it soak in Kroil ?

That's what people suggested I do on a different gun that had a lead deposit.

I’d bore scope it with one of the inexpensive imports on amazon. You’ll know then if it’s a deposit or some form of pitting. To clean, this would benefit form an overnight soaking with Foam Out or a session in the ultrasonic cleaner.

Get a .25-.27 cal bore brush and clean just the chamber.  That should remove any lead build up and you can see if there is a problem with your chamber.

kc.crawford.7 wrote:Get a .25-.27 cal bore brush and clean just the chamber.  That should remove any lead build up and you can see if there is a problem with your chamber.

+1

That brush looks a tad short. I get 2" brushes and wrap the back end with tape so I don't get pricked.

I also use cigar lighters or small butane torches in the chamber for 5 seconds then brush the bore. Amazing what comes out.

If your deposit or damage remains, chamber work by an experienced person may be required to prevent damage.

Good luck

Look here:

https://www.rimfirecentral.com/forums/showthread.php?t=1156717

Well.

Got the lead out.

Put a borescope in and here's the spot:





It's pitted and scary looking. I'm told that borescopes always make barrels look terrible ... but that looks extra terrible.

What could have caused this? It's just this one spot on the roof of the chamber. I've put a couple thousand rounds through the gun. All of it except for maybe 100 were CCI standard velocity. The rest were Wolf Match Target.

Until I saw this spot, I had only used nylon brushes and cotton patches on brass jag for cleaning. I used a bronze brush to get it clean to take this picture.


On the bright side, I shot 60 rounds out of it tonight and it fed, fired, and extracted flawlessly. The bullets went where I pointed the gun. I did put a drop of oil on the 1st round in every magazine.

But I suspect that the gigantic terrifying file on the roof of the chamber is going to collect lead with great efficiency now, and if I don't clean it often, I'll have more FTE problems.

What now?

Looks like an outline of a circle in the middle of that. There wouldn't happen to be a sight base screw in line with it, would there?

WesG wrote:Looks like an outline of a circle in the middle of that. There wouldn't happen to be a sight base screw in line with it, would there?

No, it's a stock Model 41. I just shoot the factory irons. No screws near the chamber.

Well, that eliminates the simple explanation.

Send the barrel to a smith and have them lightly run a 22lr finish reamed to smooth out the chamber, it may knock off some high spots on the gouge and help you from constantly worrying about when it's gonna mess up next.

One thing I cannot stand is a 22 pistol that malfunctions. They can go from running like a top and being my favorite pistol to running horrible and be my least favorite pretty darn quick.

The photo makes it look like depressions, but cameras and lighting can be deceptive.  It makes no sense for those to be depressions.  I'm guessing they are something on the surface of the chamber.

Maybe you could confirm this with one of those tools dentists use, sliding it up and down.  If they are only depressions, you shouldn't feel anything.  If they are something on the surface, you'll feel them, as the tool won't move over them without some resistance.


Maybe if you soak the barrel is something like Kroil for several days, you can find something that can scrape them out?  Start at one end, concentrate only on that one spot, then use the borescope to verify you're making progress.  Maybe if you made a brass tool that was just barely under the diameter of the chamber, once they get softened you could scrape them off? Maybe a bristle brush is all you need, given enough time.  

If you see progress with the bore light, you'll know it is (slowly) working.

Are you the original owner of the barrel/pistol? If not then who knows how that happened but it doesn't look like something caused by a reamer as those scares are generally circular. Maybe a cleaning rod..

As noted a 22 chamber reamer would clean up the high spots or a BRM flex hone in 22 caliber. Permanent fix would be.to reline the barrel.

I'm the original owner. I guess it's possible I damaged it with a cleaning rod, though I've always only used nylon brushes. I'm surprised brass would be able to damage the steel chamber.

I'll polish it a bit, maybe run a finishing reamer in it, see how it goes.

Looked up BRM flex hone, but they don't seem to be available for 22...

Thanks - just ordered this one off Amazon. Says it's good for 22lr chambers.

https://www.amazon.com/Research-06380-Chamber-Flex-Hone-Cartridge/dp/B00DB8D1RW

I would be more likely to take a wooden dowel and wrap some 1000 or 2000 grit paper around it and lightly go over the area of the marks or depressions.  That emery paper is really fine and would knock off the high spots.

Did the nylon brush have a steel center core?

bruce martindale wrote:Did the nylon brush have a steel center core?

All of my brushes have what look like brass or bronze cores. I've had the gun for almost a year now though. Brushes are consumable tools so I guess it's possible that I used to have one with a steel core and don't have it any more. The damage is lined up directly with the feed ramp. Maybe I was brushing that and stabbed the chamber repeatedly ... That's probably the cause. I just can't imagine the soft lead bullet of a chambering round doing this.


I got the flex hone tool in the mail today. Chucked it in a drill, put some thread-cutting oil on it, and very briefly polished the chamber. This quickly took the high spots off. To the eyeball it looks a lot better. To the borescope, it looks like this:



It's better. The scope magnifies everything of course, I bet the biggest of those pits is about a tenth of a millimeter. I just hope it doesn't collect lead and gunk from rounds as they chamber.

I cycled a few rounds through it, no stoppages. I'm going to quit worrying about it unless I start having function issues again.

Side by side, before & after the flex hone polish:

looks much better...

probably be fine now.

BTW the flex hone also will work for your firing pin hole and extractor hole to smooth them up. they actually get better the more you use them and the balls flatten out a bit.

I'd pay a dollar to know what happened to make that in the first place. Looks like someone took an engraver to your chamber.

zanemoseley wrote:I'd pay a dollar to know what happened to make that in the first place. Looks like someone took an engraver to your chamber.

I'd guess someone tried to file the feed ramp.

zanemoseley wrote:I'd pay a dollar to know what happened to make that in the first place. Looks like someone took an engraver to your chamber.

I’m in the same boat