Lead deposits in chamber of S&W Model 41

First topic message reminder :

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?

Sa-tevp wrote:

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.

Great guess. I bet that's it. But he's the original owner, I guess it's possible someone at S&W did it but dang.

Sa-tevp wrote:

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.

It would be interesting to know if the ramp lined up with that - very good theory.

I thought about jams from Russian steel-cased rounds - because they are in such a seemingly random pattern.

If you used the flex hone some more, maybe it will get better?  Whatever the flex hone was removing before had to be "above" the surface, not below.  Maybe this photo is an illusion, and all the rest is also above the surface?   If you do it some more, and nothing changes, that's the end of it, but maybe it will continue to improve?

You used it very briefly, and things improved.  Maybe if you continue to use it, it will continue to improve?

I looked at all 4 my 41 barrel ramps.  They do not look like what I see here.

mikemyers wrote:If you used the flex hone some more, maybe it will get better?  Whatever the flex hone was removing before had to be "above" the surface, not below.  Maybe this photo is an illusion, and all the rest is also above the surface?   If you do it some more, and nothing changes, that's the end of it, but maybe it will continue to improve?

You used it very briefly, and things improved.  Maybe if you continue to use it, it will continue to improve?

I did some more and it did improve -

First two pictures are reposts just so they're all next to each other in this post. Before, after a brief flex hone spin (maybe 10 seconds), and the last is after another 20-30 seconds of spinning in the chamber. Looking with the borescope, changing the angle and the shadows, these are definitely pits.



I've since put about 400 rounds of CCI SV through the gun without cleaning it. The first two magazines of 5, I didn't put the usual drop of Rem Oil on the 1st round in the magazine, and each magazine had one FTE malfunction. That was typical of the gun since the day I bought it.

After that, I resumed my habit of putting a drop of oil on the 1st round, and the next 400 or so rounds had zero malfunctions. I'm going to declare it fixed and quit messing with it.

Thanks for everyone's suggestions. I suspect I caused this damage cleaning the feed ramp with a brush that had a steel core, though I honestly can't remember ever owning such a tool or attacking the feed ramp that violently. I can't think of any other plausible way it could have happened though.

Could that have been there from the factory? I don't see that in any of my Model 41 barrels, I have a factory optics barrel, a 7 3/8 inch barrel, a 5-inch field barrel, and 2 5 1/2inch EFS barrels. I can't imagine what would have done that type of damage to your chamber unless it was improperly treated at the factory when they cut the feed ramp.

My guess is porosity in the metal before machining and went unnoticed.  If it had been done by something mechanical  after the barrel was made there would have been burrs raised and chambering almost impossible afterwards. 
A porous piece of metal with porosity that just happens to be at the chamber.

Virgil