Please help figure this out!

[KMB]

I took my PC 686 Hunter to a range last weekend along with my 4" 686. I put around 300 rds. of .38 spl through both guns, shooting several different brands of ammo through both. After cleaning, I noticed what looks to me like flame cutting on 2 chambers of front of the PC Hunter cylinder (see pics below). I thought that it may be some carbon deposits that I missed so I tried to clean them again, but to no avail. The other four chambers do not exhibit these "flame cutting" lines (or whatever they are), nor do these appear on my 4" 686. To be honest, I am a bit concerned. This is an expensive firearm and a prized piece in my SW collection.

What is going on? If this is not normal, what should I do? Send it back to SW?

By the way, here is the list of .38 spl ammo I shot. No +P stuff and no .357 mags.
-Winchester Super Clean NT 110 gr. JSP
-Fiocchi 125 gr. SJHP
-Gold Dot 125 gr. GDHP
-Reloaded ammo I got at a gun show--147 gr. lead WC and 158 gr. lead ball ammo (a bit dirty but shot without fail in both revolvers).

Thanks in advance.

 

[Iggy]

Is there a screw or a burr sticking down from the underside of the back strap?

 

[pred]

Since the marks are different distances from the barrel I am guessing that they are machining marks from S&W.
Peter

 

[KMB]

Is there a screw or a burr sticking down from the underside of the back strap?

Nope, no screws or burrs. Plus, the marks are not in the same place. On one chamber, the mark is about 1 mm further on the cylinder than on the other chamber.

Since the marks are different distances from the barrel I am guessing that they are machining marks from S&W.
Peter

I haven't noticed these marks prior to shooting it. Not saying that they were not there, but it is highly unlikely. After I purchased the revolver (approx. a month ago), I looked it over thoroughly. I would have noticed these marks for sure.

 

[yska08]

Send your pictures to S&W, maybe they can tell you more? Strange markings indeed!

 

[Bullseye Smith]

What did it look like before you cleaned it? Was it black soot and did you have any lead that you cleaned off. Plus did you shoot some rapit fire? Was there build up around the rear sight screw?
If all the above is true it could have been some hot load even from a 38 with a double charge. With the rapit fire the hot lead could have done like a flame cut, just guessing. Polish it off and watch it at the next trip.

 

[44forever]

Drag a thumbnail across one of them.

Does it catch on the mark. If so then it shows some kind of cutting. If the thumbnail doesn't catch but does change the appearance of the mark, it is probably a residue deposit and can be polished off using Lead Away coth or something similar.

 

[KMB]

What did it look like before you cleaned it? Was it black soot and did you have any lead that you cleaned off. Plus did you shoot some rapit fire? Was there build up around the rear sight screw?
If all the above is true it could have been some hot load even from a 38 with a double charge. With the rapit fire the hot lead could have done like a flame cut, just guessing. Polish it off and watch it at the next trip.

Black soot was on the cylinder. I did not see any lead build up there. Did not see any build up around the rear sight screw either. The revolver was not shot in a rapid fire mode. How do you recommend polishing it off and with what product?

After cleaning the gun with Hoppes 9, and then again with Rem Oil lubricant/cleaner, I finished off by wiping it down with ADCO cleaning/lead removal cloth. Marks are still there. Can you recommend something better?

Does it catch on the mark. If so then it shows some kind of cutting. If the thumbnail doesn't catch but does change the appearance of the mark, it is probably a residue deposit and can be polished off using Lead Away coth or something similar.

I think that the thumbnail does catch on the mark, but barely (I'm not at home right now so I can't confirm for sure). The marks do not appear to be deep but are clearly visible.


The weird thing is that the marks appear only on two chambers, and only on the PC Hunter. No marks of this sort appear on my other 686 and it had the same diet of ammo. I was basically shooting 2-3 loads in one revolver, then switching to the other. Wanted to see if there was a substantial difference in accuracy between the two revolvers in accuracy with different types of ammo (there wasn't, at least at the distances I was shooting).

 

[Bullseye Smith]

I would take a marker and mark the tube that has the mark on it and then polish it off. This gives you a reason to go to the range to shoot and see if they are there again on the same openings. If they are there then I would call S&W about it.

 

[R. G. Amos]

Perhaps there was debris of some sort trapped between the cylinder and top strap. The debris eventually worked its way out after scoring only these sections of the cylinder. I had something like this happen to the top of a model 41 slide which was scratched when a grain of sand became lodged between the top of the slide and bottom of the rear sight.

 

[1HAWKEYE]

KMB, No need to worry about these lines. They are caused by shooting lead bullets.I can't explain how they get in just those spots on the cylinder flats but the softer the lead the worse the build up.My 14-3's & my 17-3 are the worst offenders.(you should see one after 500 rds) It can be cleaned off using dry (no oil or solvent) 4 ought steel wool pressing very lightly paralell with the build up. 1HAWKEYE

 

[KMB]

KMB, No need to worry about these lines. They are caused by shooting lead bullets.I can't explain how they get in just those spots on the cylinder flats but the softer the lead the worse the build up.My 14-3's & my 17-3 are the worst offenders.(you should see one after 500 rds) It can be cleaned off using dry (no oil or solvent) 4 ought steel wool pressing very lightly paralell with the build up. 1HAWKEYE

Thanks for the advice, Hawkeye. I'll give that a try.

 

[KMB]

Does it catch on the mark. If so then it shows some kind of cutting. If the thumbnail doesn't catch but does change the appearance of the mark, it is probably a residue deposit and can be polished off using Lead Away coth or something similar.

Ok, I can now confirm that nothing catches on the marks--meaning that it is not flame cutting. That makes me feel better already. It appears to be really, really, really bad lead build up. The ADCO Lead-Away cloth is not working. Scrubbing with heat treated (hard) nylon brush and Hoppes 9 also fails to produce any results.

Before I try steel wool or fine grit sanding paper, can somebody recommend another lead cleaning cloth which--in your actual experience--worked well on hard-to-clean deposits?

 

[LDThornton]

Ok, I can now confirm that nothing catches on the marks--meaning that it is not flame cutting. That makes me feel better already. It appears to be really, really, really bad lead build up. The ADCO Lead-Away cloth is not working. Scrubbing with heat treated (hard) nylon brush and Hoppes 9 also fails to produce any results.

Before I try steel wool or fine grit sanding paper, can somebody recommend another lead cleaning cloth which--in your actual experience--worked well on hard-to-clean deposits?

Try some Nevr-Dull. Get it in the automotive section at Wal-Mart.

 

[dbarale]

Copper Chore Boy pad, it has to be copper. It may leave a slight coppery tint that will easily be removed with the lead-a-way cloth. It works for the bore too...

 

[JohnK]

I second the COPPER pad.

I know some of you love steel wool, but it'll scratch the snot out of your gun, and certainly damage bluing.

 

[1HAWKEYE]

The steel wool trick won't harm the bluing if you only use dry 4 ought steel wool with very light finger presure.(NO ELBOW GREASE) I learned this trick from an old bullseye shooter when I was a teenager and his stuff looked like brand new when he was done cleaning.I do agree with JohnK though if 2 or 3 ought steel wool is used or used wet with oil or solvent with a lot of pressure you might as well use corse sand paper.Good Luck Hawkeye

 

[5Wire]

I second the COPPER pad.

I know some of you love steel wool, but it'll scratch the snot out of your gun, and certainly damage bluing.

Bronze wool, Triple or Quadruple O is pretty soft and with oil is useful on blued guns. No soap involved.

 

[KMB]

Bluing is not a concern for me--the "patient" is a stainless revolver. However, I do not want to add any unnecessary scratches to the surface so I will probably feel safer with copper or bronze wool.

Thanks for all of your suggestions, guys. I'm learning a ton!