I bought my lightly used 629-4 Classic (with a 6.5" PowerPort barrel) last year to use as a "fun gun," something to pop off a dozen or two rounds at the range after I finish training with my EDCs. The last time I shot it, however, I had the range all to myself (don't you love it when that happens!) and I had the opportunity to give it a thorough wringing out. Starting with a thoroughly cleaned gun, I shot just over fifty rounds of factory 240gr. JSPs, a mix of Winchester White Box (which I've used before) and MagTech (a new purchase). When I went to clean it, I was surprised to see the pictured marks on the outside surface of the cylinder at the front of each chamber.




They obviously correspond to the factory-drilled 'scope mounting holes in the top strap. The screws do *not* extend through the top strap, but the cylinder markings make it look like they were dinging into each chamber on firing. Is this normal? As I said, I've never fired that many rounds at one session before, so I don't know if it's the number of rounds fired, the ammo used (first time firing the MagTech), the gun (everything appears tight: timing is right on and B/C gap is .003-.005") or if I'm over-reacting to a normal occurrence (the markings were on the surface only and cleaned up easily). Help!

Steve

I have the same gun and mine does the same thing..

Nothing really to worry about, S&W explained the " dinging " as marks being made by the combustion gasses of round being fired comming back and being redirected from the front screw hole down onto the cylinder causing a "swirling effect" in the fouling marks..

( Don't know if it's true or not, but sounded good to me..)

ps.. I also get the same marks on my .500

Sounds like a job for JB Weld. I would fill the holes and see if that takes care of it. You can alway take the screw out and run a tap down through it to clean out the JB if you need to. Just a thought.

The offending screw hole is for the screw that holds the rear sights in place. The stain is as much surface oxidation due to the high temperature of combustion as from combustion products themselves. The latter clean up easily with solvent or oil (I use REM Oil). The oxidation cleans up with a mildly abrasive cleaner like Flitz or toothpaste.

My experience with MagTech ammo has been that is it generally sooty, so it's no surprise to see those markings... and it won't be that last time when using some of the import stuff.

Chalk it up to dirty ammo, which is bound to happen from time to time, and keep having fun with your 629-4. And I don't know if it was a serious comment or not, but there's absolutely no reason to apply JB weld to it as a "fix".

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Conrad
SWCA #1830 SWHF #222

Thanks to everybody for the reassurances. I love the gun; it's a real tackdriver, especially with Hornady XTP ammo... when I control my flinching, that is!

Steve

Same thing happened to my blued 29-5. Wore off the bluing on each cylinder under the tapped holes. Sent it to S&W. They reblued the cylinder and plugged the front top strap hole. I am not the original owner so I was charged for the service. When I got it back I fired a few rounds and bluing still wore off the front of each cylinder slightly. However it fixed the top of each cylinder problem.

Those are the marks of quality. Embrace them, show them off. It proves you don't sit around with polish and a terry towel, talking about guns all the time.

My 629 MG has the same tapped holes but the front one that is causing the problem in your gun has the screw cut off exactly flush. It does not make marks like yours, at least with the ammo I have used (mostly reloads using unique). The point is maybe if you get a screw long enough that it protrudes slightly and then carefully cut it down until it is flush your "problem" will go away.
edit: To clarify, I do of course get powder burn marks on the cylinder, just not the round marks.

Anything I shoot with the number .44 or .45 gets a lot of powder residue everywhere. Since you have a stainless gun you can get use a lead wipe on the cylinder to remove all offending black gunk without any worries about marring the finish.

Same thing happens to my 624 but it's got no holes in the top strap. So my marks are just a linear looking powder mark, no circular hole shaped marking. The gasses escape upwards when fired hit the bottom of the top strap and are forced back down onto the cylinder causing this. I kind of like the way it looks actually lol.

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~ S&WCA No.2159 ~

I have a 629-4 Classic (a 5") and it doesn't make a mark like yours. My 629-3 Classic didn't either. My rear sight retaining screw isn't perfectly flush. Interesting. I shoot reloads almost always loaded with H110 powder.

As stated previously, those marks clean up easily.

Good photography!!

Excellent comment. I feel much better now!

a leadaway cloth will wipe them away easily

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SWCA#2208
KK4EMO

I have a 6.5" 629-3 and a 6.5" 629-5 PowerPort and neither one does that. But I have a 5" 629-3 Classic DX that does! It cleans right off, so I never worried about it.

Ed