Anyone else's breech have these mill cuts?

[ToneSurfer]

I noticed these machine/mill cuts in the breech of my gun (CM9) right after I had it apart for cleaning (mainly because they are pita to clean out). Are they there on purpose and if so what might that purpose be?

Gun shoots perfectly fine and I've no issues. Just curious.

Also, that darkening from powder burning I can not just clean up. Any suggestions or just live with it. I've scrubbed it as much as I dare with a wire brush.

PS: My wife's Cannon SD1200 camera rocks.

http://i893.photobucket.com/albums/ac135/tonesurfer/065.jpg

[jimsea]

Wow.....what a great pic.


Mine has the same machine marks. So, I will assume they are typical.

Same staining as well on the slide.

[ripley16]

Wow.....what a great pic.


Mine has the same machine marks. So, I will assume they are typical.

Same staining as well on the slide.

Ditto on the picure quality, machining marks, (though not as pronounced), and discoloration.

[jimsea]

Ditto on machining marks, (though not as pronounced)...........

lol...........that camera could make a pimple look like Mt Ranier.

[OldLincoln]

Yeah, if you look real close you can see the nanobots eating up that carbon residue.

[ToneSurfer]

Oh hey just to clarify what I'm talking about. Its not the "scratches" or marks on the breech face directly, its the rounded "cutouts" (i call em) that are in the center top of the picture. You can see 2 nice square inside corners, then about half of that corner is rounded out. Like a drill bit was used to "unsquare" the corner. I'm not worried about the scratches at all.

And yeah that camera is sweet. I was shocked at how clear a close up it was able to produce. It's a pocket camera, smaller than my CM9 :)

[wyntrout]

Flitz should help remove the black. I don't worry about that stuff unless it starts to build up... then I use a jeweler's screwdriver to scrape it off, especially around the breech of the barrel and barrel hood.

Wynn:)

[Popeye]

My PM9 has them also, but not as big as that camera makes them out to be. To be perfectly honest I never even noticed them before, maybe because my guns slide is black and the eyes aren't what they used to be either.:( Seems to be some kind of relief cut for whatever reason your guess would be as good as mine, if not better. Nice camera by the way.

[OldLincoln]

Oh, you're talking about the half drilled on each side overpressure vent safety feature!! Did you have to pay extra for that? :) Just kidding, but nothing to be concerned about. Some here are milling experts and will probably say something about pilot alignment holes or something in the milling process to ensure the breech face is absolutely flat. Like our old friend Shultz... "I know nothing", but it's likely okay.

[Tilos]

OK, after a life time of looking a machined surfaces, the faces and steps on the breech face appear to be BROACHED, not milled. (to me:o).

The circular pockets in the corners are MILLED and are probably additional clearance of something.

YMMV,
Tilos