Forcing cone cleanup

[browntown]

So I've been battling lead splatter with my 686-5 around the barrel extension. The forcing cone is heavily leaded. I also get occasional splatter coming back to my face. I need to fix it.

I've spent quite a bit of time reading the literature and I think I want to chamfer the forcing cone to 11deg.

Before anyone asks the cylinder gap is .007 which although not ideal, is within spec.

Since I can't be sure that the lead in the forcing cone is the culprit and shaves off lead, or if the magnum loads are blowing out the lead rings from 38 shells, I need a super clean baseline.

I've been perusing the brownell's catalog and have determined that I can spend hundreds of dollars on my speculation.

For the cylinder, I'll soak it in solvent and brush it. Or if it needs it, I'll spring for the de-leader reamer. It's an expensive little tool, but I think it is one I can use in the future.

For the forcing cone, I've brushed quite a bit, but hasn't done much for me. Next up I was thinking of using a piece of "lead away" cloth. Outside of the taylor brass patch method, does anyone have any better ideas?

Once everything is spotless, I'll throw 100 magnums down range and see if she still spits and splatters. If so I think I'll need to buy the actual 11deg throat chamfer tool, as well as the incredibly high priced plug chamfer checker. That sounds like a fun 150$ project.

So base question is how to get everything super clean to establish a baseline before I dump money on the throat chamfering kit?

While we're on the subject, I took a looksy at the forcing cones of my other smiths and they look fine, except my 940 has heavy machining marks. It almost looks like a dull chamfer bit chattered on the throat. Is this normal? If I get the chamfering kit this makes me want to get the polishing bit for it as well. See 2nd pic

 

[alde]

I will follow this thread with great interest as I have the same problem. I have never really been able to get a forcing cone really clean and lead free. I did buy some pure cooper scrubbing pads. I thought a wad of that might help knock the lead off but have not tried it yet. Sounds like a good early Sunday morning project before everybody gets up.

 

[ogilvyspecial]

I use a Lewis Lead Remover whenever a gun of mine looks like it needs it.

 

[brucev]

The following is my opinion and only my opinion. I would suggest that you begin with a thorough cleaning of the throat, cylinder, etc. Purchase and use a Lewis Lead Remover as it will do this job completely

Do check end shake and head space before doing any work that is permanent. If end shake needs attention, deal with that using end shake washers (Brownells). If head space is a problem, I don't know what to tell you as I have no idea how to fix it.

Look at the throat. It appears there are machining marks present. If this is the case, you might first want to contact S&W and request that they correct this. Your revolver has a life-time warranty. As this would be a manufacturing issue, it would certainly be something that S&W would deal with. They might simply clean up the throat. Or, they might fit a new barrel. Bring to their attention the current barrel/cylinder gap of .007 inches and the lead spitting.

If you decide you want to proceed with chamferring the forcing cone, it would be wise to consider sending it to an experienced gunsmith/repair facility. You might get it right first time out the door. You might not. But an experienced gunsmith who has previously dealt with chamferring forcing cones and who has the equipment on hand would likely produce better results. Given the cost of the tool required, etc., you would likely come out with less expense. HTH. Sincerely. brucev.

 

[tomcatt51]

"Magnum" loads with cast lead in .357 mag can lead. If you are shooting hi-velocity lead loads you might look at your load and bullet hardness before attacking the forcing cone. You could easily have a loading issue rather than a forcing cone issue.

 

[TexinMaine]

Have you checked the timing?

 

[gruntdeputy]

Lewis Lead Remover

I had a similar complaint of my Model 19 after many years of service of shooting my department’s dirty lead range ammo. I used a Lewis Lead Remover and cured the problem. I'd try this before anything else.

Caution: wear gloves! Halfway through the project it looked like I had a black glove on my left hand.

Frank

 

[tomcatt51]

I've had issues with leading from 38 specials when I've made bad reloading choices. I clean up the mess using a bore brush wrapped with chore boy. To get the forcing cone clean can require doing the chore boy wrapping in the cylinder window and pulling it from forcing cone to muzzle.

 

[Hexer]

I agree it may be a timing issue. Use a range rod to check the barrel cylinder alignment.

 

[TexinMaine]

Check timing

A simpler way is to slowly cock into single action then rotate cylinder by hand. If it moves and you hear it click into place timing is off, if it is solid and no movement it should be o.k.

 

[browntown]

Timing is good, I followed the procedure from the Kuhnhausen book. I suppose if I'm ever going to send it in to the factory now is the time to do it before I go bobbing the hammer, thinning the trigger and installing the apex firing pin sitting here. I figure if there is any threat to them ripping out after market stuff, better to do it now. I guess I'll remove the sdm and weigand sights too just to be safe.

I'll call them and see what they say. If they fix it for free it might save a lot of dough.

 

[dfariswheel]

The only really effective method of cleaning a revolver forcing cone is the Lewis Lead Remover.
All the older revolver shooters owned one and used them often.

The Lewis should be used even if all you shoot are jacketed bullets, since the Lewis also cuts the copper fouling off.
Of the S&W Model 19 revolvers that had forcing cone cracks, most had badly fouled cones.
The Lewis will prevent the build up.

Before altering a gun, the smart move is to eliminate other possibilities like a fouled cone.
The Lewis kit is cheap insurance and cleans a critical part of the revolver that nothing else can get to as well or as fast.

Note the video link on the page that shows how to use the kit:

LEWIS LEAD REMOVER - Brownells

 

[browntown]

OK, I'll clean the cone with the lewis tool (on backorder, gotta wait a little), make sure the cylinder is spotless, and run some rounds through it. If it starts plating to the side with lead splatter again, it'll go back to the factory. Thanks for all the help.

 

[chief38]

I too have owned & used a Lewis Lead remover for over 35 years. If you are a serious revolver shooter you NEED to own one! Inexpensive, efficient, quick and safe, they will get the lead out 1,2,3!

For plinking a and target shooting I like 158 grain RNL bullets which are very accurate, and reduce the leading to almost nothing. If you still are getting significant lead build up with them, then yes I would check the timing.

Chief38

 

[Forrest r]

It almost sounds like you have several small issues going on rather than pin pointing one big issue.
Absolutely clean everything, a Lewis lead remover or a piece of Chore Boy copper scrubbing pad (copper steel wool) put on a bore brush will work. I like the Chore Boy & have used it for years with great success. I just put a big wad of it on the end of a bore brush & screw the bore brush into a piece of cleaning rod (no handle). Then I chuck the piece of cleaning rod up in a cordless drill. I clean the cylinders & the forcing cone this way, it cleans them in seconds.
Once you get everything clean you should slug ALL of your cylinders & you bbl. When you slug your bbl go slow & feel for tight spots. Especially where the bbl screws into the frame. The cylinders should all read the same dia. & the #’s you get should help you narrow down your leading issues.

A couple of things to think about:
.007” is at the far end of the specs & can cause problems if there’s any movement/slop in the timing of your revolver.
Once lead starts to build up in the forcing cone it does a snowball effect & worsens rapidly. IE, the more the dia. Constricts the more lead it shaves & the more lead gets deposited per shot.
The hotter (pressure& speed) the load is the more it has to conform to the specs of the pistol. Light loads are forgiving & will mask reloading issues that heavy loads tend to bring out.

I’ve owned a 586 since 1987, bought it new & it has been my primary 38/357 revolver since then. After shooting countless 1000’s of rounds in it I had to send it back to S&W to have them rebuild it. I shot that pistol enough to wear the timing out. They rebuilt it & recut the forcing cone for me. Just recutting the forcing cone does nothing if all the pistols issues aren’t addressed. A 1/1000 of here & 4/1000 of their add up to trouble.

On a side note, that 586 always did shoot different with full house 357 loads. I would size the 38spl & light 357 loads to .358 & never have a problem. When I’d shoot/load full house 357’s in it I’d have to size the bullets to .357 or leading would occur rather quickly in the forcing cone area. One of my all time favorite powder/bullet combo was WW820 pull down powder & the Lyman 358311 bullet. I used to order 4 8# jugs of that powder at a time & shoot full house loads (13g) by the 1000’s. The cylinder’s dia. was tight in that revolver I’d get leading problems only with full house loads. When I dropped the bullet dia. to .357 for the full house loads only, the leading issues cleared up with the full house loads.

Let us know what you find & good luck.

 

[Tom C]

When I get a new revo in .357 I take it apart, clean it, and check everything. As a matter of routine, I cut the forcing cone to 5 degrees. An 11 degree cutter probably won't clean up the forcing cone and you will end up with a cone with two champfers: 11 degrees on the outside, and 7 to 8 degrees further in. 5 degrees has worked very well for me. I use the cutters from Brownell's.

 

[climbcut25]

In response to your statement that "It looks like chatter from a reamer"... I will dis-agree with you. The marks are radial in nature. This is an indication of a single point tool. (Boring bar) Or a chipped reamer. If it where chatter, the marks would be axial in nature and look like a washboard going around your forcing cone, not a ring. If you have a lathe or a friend with a lathe... Turn up a brass cone able to be driven by a bushed cleaning rod from the muzzle, and lap away. I say lap, because it is slow and needs to be checked often. Reamer will be quicker but more dangerous.

Being a machinist, I am too stupid to be afraid of ruining my guns. And too proud to take them to a smith. If you are not one of the above... Don't be like me.

 

[browntown]

^That's helpful actually. The 9mm revolvers (547 and 940) mostly shoot copper washed bullets so the problem of the rough forcing cone is less prominant in regards to leading. The 686 is going to soon be shooting 230gr bowling pin loads from penn bullets. I want these issues solved before I start throwing the big logs down the pipe. So I'm waiting on the lewis lead remover to be in stock from Brownells. I'll chore boy the cylinder and forcing cone and test the gun within the next week. Then I'll call the factory if things are still acting up. Thanks for all the help.

 

[WR Moore]

I agree with the Lewis Lead Remover idea and that bullet size/hardness may be issues.

The circular grooves in the forcing cone are from either a burred reamer or chips that got caught during the reaming operation. The factory doesn't single point forcing cones. Lapping the cone is possible. A brass cone with a matching taper can be used. I generally cheated and glued a piece of emery or crocus cloth on the taper plug.

Also as noted, someone who does this stuff for a living (or has the skills and over invested in a hobby) has all the tools and would probably do the job for less than it will cost you to get the tools. The factory is also good, but if measurements are within factory tolerances, they won't be worked.

Depending upon the specs of your cone, a single point tool might be able to clean up the forcing cone while keeping it within spec, but you'd be paying for pulling and reinstalling the barrel.

 

[climbcut25]

Tom C, Is that 5 degree included angle or 5 degrees per side?