S&W 686-4 leading mystery

[oldhenry]

This 686-4 is + model used for plinking & SD using .38 Spec. for 95% of the shooting. It shoots cast boolits exclusively usually propelled by 4.4-4.5 gr. of HP-38/231. Most boolits weigh around 160 gr. except the #358429.

The front edge of the cylinder accumulates lead deposits on the un-fluted portion. The only way I've been able remove to these deposits is with #000 steel wool. The face of the cylinder accumulates an extremely thin layer of lead That also requires steel wool to remove. I had a 6 shot 6" 686 that I shot much more with primarily .357 cast boolit loads & it never had these problems. I have 4 Ruger S/A, a S&W 25-2, a Ruger GP100 (SS) & gave one son a S&W "15 & the other son a S&W 25-5 and none of these have this problem. The Ruger S/As get used heavily.

All above mention revolvers use cast boolits exclusively & of the same alloy (COWW) as the 686-4 and BAC lube is used on all boolits.

The bore does not lead & there is no leading in the forcing cone or the rear outside surface of the bbl. that protrudes through the frame.

Images:
#1 & #2: lead deposits on front edge of cylinder (none on the fluted front edge).
#3: Cylinder front showing very thin lead deposits.
#4 & #5: Right side & Left side view of frame end of bbl.: note groove @ end of bbl. apparently made by factory.
#6: minor lead deposits on lower front of cylinder window (this leading only occurs on the cylinder pivot side).


The lesser degree of leading that takes place on the frame @ the lower front of the cylinder window is easier to remove.

The shallow trough (groove) on the upper inner frame @ the rear of the bbl. I assume was made @ the factory (?).

I'd appreciate any input.

Thanks,

Henry

[Forrest r]

That "shallow trough (groove) on the upper inner frame @ the rear of the bbl" is what's known as flame cutting.

You're leading is coming from what's called gas blow-by. You're using a light load of powder and it isn't expanding the base of the bullets enough to seal the bullet/cylinder fit and gas is escaping around the base of the bullet flame cutting as it goes. Then the gas with the flame cut lead is depositing lead everywhere it goes.

It's pretty common advice that you'll lose +/- 10fps for every 1/1000th's of cylinder gap and when using 38spl's in a 357 cylinder.

You're not getting leading in the bbl because you have the correct bullet/bbl fit. In the cylinders, not so much. You're problem is the bullet/cylinder fit. (.357" bullet)

Some simple fixes:
Use a larger bullet diameter
Use a softer alloy
Use more pressure/powder
Move the bullet out further/longer oal

Take a couple bullets you're loading and drop them in your cylinders. Note where the bullet noses end/sit in the face of the cylinders. That is where you want to seat/load/oal your reloads.

I love bullets that have 2 crimp grooves!!! The Mihec 640 for the 38spl's/357's has become my favorite bullet to use when reloading the 38spl's.

[IMG][/IMG]

Doesn't matter if I use the reloads in any of my 38spl's or 357's. The bullet always gets crimped in the bottom crimp groove. I also like to move the wc bullets out further/longer oal when using them with the 38spl reloads/357 firearms. I crimp the h&g #50's in the middle lube groove.

[IMG][/IMG]

Those reloads pictured above produced these targets. The targets are not hand picked/cherry picked targets by any means. That are nothing more than the actual test targets I used to tests loads for a 686. 6-shot groups @ 50ft testing 38spl loads for a 686.

[IMG][/IMG]


What the 686 looks like after a 200 round range session with those reloads pictured above.
[IMG][/IMG]

As you can see in the picture above, that 686 has a buildup starting to form in the same area's that you pictured in your post. The difference is my bullets/reloads only have carbon building up on the firearm. Your's has carbon & lead. The bullets/loads that I use are:
8bhn/9bhn
sized to .358"
+/- 15,5000 psi

The other thing to note is in the 200 round range session picture posted above you don't see any soot on 1 side of the case mouths. Seeing soot on 1 side of the case mouths ='s the pressure of the load is too low to get the brass to expand/seal the cylinders. If you see blow-by on your cases you'll see blow-by on your firearm.

[jeepyj]

Forrest r - excellent response, I pulled out several helpful points and will use your response as a reference

[Petrol & Powder]

All good input from forrestr and well written. I'll add that the minor deposits on the cylinder and frame are largely cosmetic and not serious. In addition to the good advice from forrestr on how to reduce those deposits, I going to toss in some methods to deal with them after they appear: The use of one of the "lead away" cleaning cloths would be preferable over steel wool. A pencil eraser also works well on stainless. After the gun is clean and dry, a coating of non-abrasive car wax will make subsequent cleanings easier.

If you're not getting leading in the barrel and the gun is shooting accurately; I'd be reluctant to go to a larger diameter bullet. I think forrestr's advice is spot on but I might go with a softer bullet or a little more powder before I tried a bigger bullet.

[oldhenry]

That "shallow trough (groove) on the upper inner frame @ the rear of the bbl" is what's known as flame cutting.

You're leading is coming from what's called gas blow-by. You're using a light load of powder and it isn't expanding the base of the bullets enough to seal the bullet/cylinder fit and gas is escaping around the base of the bullet flame cutting as it goes. Then the gas with the flame cut lead is depositing lead everywhere it goes.

It's pretty common advice that you'll lose +/- 10fps for every 1/1000th's of cylinder gap and when using 38spl's in a 357 cylinder.

You're not getting leading in the bbl because you have the correct bullet/bbl fit. In the cylinders, not so much. You're problem is the bullet/cylinder fit. (.357" bullet)

Some simple fixes:
Use a larger bullet diameter
Use a softer alloy
Use more pressure/powder
Move the bullet out further/longer oal

Take a couple bullets you're loading and drop them in your cylinders. Note where the bullet noses end/sit in the face of the cylinders. That is where you want to seat/load/oal your reloads.

I love bullets that have 2 crimp grooves!!! The Mihec 640 for the 38spl's/357's has become my favorite bullet to use when reloading the 38spl's.

[IMG][/IMG]

Doesn't matter if I use the reloads in any of my 38spl's or 357's. The bullet always gets crimped in the bottom crimp groove. I also like to move the wc bullets out further/longer oal when using them with the 38spl reloads/357 firearms. I crimp the h&g #50's in the middle lube groove.

[IMG][/IMG]

Those reloads pictured above produced these targets. The targets are not hand picked/cherry picked targets by any means. That are nothing more than the actual test targets I used to tests loads for a 686. 6-shot groups @ 50ft testing 38spl loads for a 686.

[IMG][/IMG]


What the 686 looks like after a 200 round range session with those reloads pictured above.
[IMG][/IMG]

As you can see in the picture above, that 686 has a buildup starting to form in the same area's that you pictured in your post. The difference is my bullets/reloads only have carbon building up on the firearm. Your's has carbon & lead. The bullets/loads that I use are:
8bhn/9bhn
sized to .358"
+/- 15,5000 psi

The other thing to note is in the 200 round range session picture posted above you don't see any soot on 1 side of the case mouths. Seeing soot on 1 side of the case mouths ='s the pressure of the load is too low to get the brass to expand/seal the cylinders. If you see blow-by on your cases you'll see blow-by on your firearm.

Forest r,
I really appreciate your very informative reply.

1.I checked the 100 empties that I fired yesterday & no soot was evident.
2. 4.4-4.5 of HP-38/231 is about max & approaching +P, so I can't adjust upward there.
3. I do have a .359 sizing die (I've been sizing @ .358) & will start using it on the .38 spec.
4. I will add pb to the COWW for a softer alloy.
5. I'll try your method of finding the best boolit to use (I suspect it'll be #358429).

Now that I understand the problem I believe there another suspect .........there was a period of time where I used the SAECO #382BB boolit for most .38 spec. loads. I stock piled quite a few loads with that boolit. I can see now that the BB did not help the situation.

Two of my RBH are .357 & I'll check them for flame cutting.

Once again, many thanks.

Henry

[oldhenry]

All good input from forrestr and well written. I'll add that the minor deposits on the cylinder and frame are largely cosmetic and not serious. In addition to the good advice from forrestr on how to reduce those deposits, I going to toss in some methods to deal with them after they appear: The use of one of the "lead away" cleaning cloths would be preferable over steel wool. A pencil eraser also works well on stainless. After the gun is clean and dry, a coating of non-abrasive car wax will make subsequent cleanings easier.

If you're not getting leading in the barrel and the gun is shooting accurately; I'd be reluctant to go to a larger diameter bullet. I think forrestr's advice is spot on but I might go with a softer bullet or a little more powder before I tried a bigger bullet.

Thanks for the tips on removing the lead. The #000 steel wool is a little messy & I don't like what it does to the S&W SS finish.

I will try a softer alloy & use all plain base boolits as a 1st. step. To increase the load would mean going to .357 loads which is not very pleasant for 100 round stints with this 4" bbl. + the round butt grip.

Henry

[Guesser]

I have experienced leading in S&W stainless revolvers enough times over the years that I no longer own any S&W stainless revolvers. Using the same alloy and casting techniques and formula for all blue steel revolvers of all calibers and all Colt, Taurus and Ruger stainless revolvers. Only the S&W consistently leaded, some guns it was forcing cone, some it was bore and on a 66-5 it was the chamber throats to the point that I carved the lead out with a modified x-acto knife. I have no idea why the S&W stainless sucks like it does, I have asked a lot of casters, shooters and knowledgeable people. No clue, some tell me it is just me; I agree; but why???? I don't own any S&W stainless revolvers because of the problem. I don't shoot jacketed bullets in my revolvers.

[oldhenry]

I have experienced leading in S&W stainless revolvers enough times over the years that I no longer own any S&W stainless revolvers. Using the same alloy and casting techniques and formula for all blue steel revolvers of all calibers and all Colt, Taurus and Ruger stainless revolvers. Only the S&W consistently leaded, some guns it was forcing cone, some it was bore and on a 66-5 it was the chamber throats to the point that I carved the lead out with a modified x-acto knife. I have no idea why the S&W stainless sucks like it does, I have asked a lot of casters, shooters and knowledgeable people. No clue, some tell me it is just me; I agree; but why???? I don't own any S&W stainless revolvers because of the problem. I don't shoot jacketed bullets in my revolvers.

I believe you have a valid point. My Ruger GP100 in .44 special has no such issues using the same alloy & same lube (the only other SS revolver that I own). I shoot the Ruger more than the 686. I have my own range & shoot 4 or 5 days a week.

Henry

[vzerone]

COWW if they are air cooled aren't "too" bad, but you could soften them up and see what happens. You can always go as big on the bullet diameter that your chamber will let you chamber a round. This does depend on various case thicknesses too. Don't worry about a fat bullet getting into the bore. The one thing, and I believe you already know this, is never shoot an under sized bullet. HP38/231 won't soot much because it's a relatively clean burning powder. If you want to test that sealing theory out shoot a "dirtier" burning powder like Unique with the same pressure/velocity load to match the HP38/231.

[Three-Fifty-Seven]

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[gnostic]

My guns all get leaded, like yours, within a few hundred rounds. I've always thought it was the result of soft lead, range scrap bullets. On my stainless revolvers, I use a treated lead wipe away cloth and a used up bore brush on blued finish to remove lead. I wouldn't under any circumstances use steel wool...

[oldhenry]

My guns all get leaded, like yours, within a few hundred rounds. I've always thought it was the result of soft lead, range scrap bullets. On my stainless revolvers, I use a treated lead wipe away cloth and a used up bore brush on blued finish to remove lead. I wouldn't under any circumstances use steel wool...

The lead deposits @ the front edge of the cylinder are so thick that I can feel them with my finger nail. I plan to try all lead wipe products, but I have my doubts. I've tried Shooter's Choice Lead Remover ,but it does not help.The deposits are so stubborn that when I open my gun safe I usually pass over the 686 knowing that after a 100 or so rounds, I'm in for an extended cleaning session. My blued guns (and my GP100 SS)only require a simple rub down with CLP & a few passes with a tooth brush and about every 300-400 rounds a well worn M1 chamber brush on the .38/.357 cylinders & a worn out 20 ga. brush on my .45 & .44 cylinders (followed by a few patches).

I'm like Guesser: I'll never buy another S&W stainless revolver again. I'd trade it for a 586 in a heart beat.

Henry

[Art in Colorado]

I have said this many times before that the 686-3 and -4 are some of the best 357's ever made. I have owned many of the 686's and I find them the best. Hope you get your reloading solved.

[curator]

Removing lead deposits without scratching your guy is easy using bronze wool instead of steel wool. Bronze is softer than steel, won't remove the bluing, and cuts through lead nicely. Use it dry for lead removal or add a drop of oil if removing rust. You can find bronze wool in three grades at most stores that sell boat paint or fine cabinet making supplies. Wrap around a nylon bore brush to remove lead deposits there too!

[oldhenry]

Removing lead deposits without scratching your guy is easy using bronze wool instead of steel wool. Bronze is softer than steel, won't remove the bluing, and cuts through lead nicely. Use it dry for lead removal or add a drop of oil if removing rust. You can find bronze wool in three grades at most stores that sell boat paint or fine cabinet making supplies. Wrap around a nylon bore brush to remove lead deposits there too!

Thanks for that tip.
Henry

[tazman]

I happen to have a 686-3 with the 8-3/8" barrel. I have made no modifications to it other than a change of grips to make it fit my hands better.
I have fired several hundred rounds through it since I got hold of it and it shoots better than I would ever have believed.
I clean the cylinder and surrounding area after each range session but never clean the barrel. It simply doesn't gather lead. Always shiny.
I just make sure it will always function when I need it to.
I clean the powder residue off the sides of the cylinder and top strap area with Hoppes. Occasionally, after a particularly long session, I will need to take the crane and cylinder off the gun and let the cylinder soak for a bit to get particularly stubborn fouling to loosen, but that doesn't happen often.
You might try soaking the cylinder down with Kroil and letting it set overnight. It seems that stuff will loosen almost anything given a little time.

[Forrest r]

Not for leading but it is excellent on "SS steal only" firearms for removing the carbon build-up on the front of ss revolver cylinders/frames/top straps/etc..
[IMG][/IMG]

Do not use this on any blued firearm. It will take the blueing off!!!

[oldhenry]

Tazeman,

I haven't tried Kroil for removing lead, but have used it for other applications........I'll give it a try.

Thanks for the tip.

Henry

[oldhenry]

Not for leading but it is excellent on "SS steal only" firearms for removing the carbon build-up on the front of ss revolver cylinders/frames/top straps/etc..
[IMG][/IMG]

Do not use this on any blued firearm. It will take the blueing off!!!

I really don't have a problem with carbon buildup. A wipe down with CLP after each range session & an occasional use of a chamber brush does the trick. My problem is leading of the cylinder only.

Henry

[Rattlesnake Charlie]

A friend of mine has the same revolver, and likes it spiffy clean. I had him use some aerosol carburetor cleaner from WalMart to remove the carbon and minute amount of lead. It works great. Keep it off plastic and rubber parts.