Cylinder leading

[Cherokee]

In my new 686 I have experienced leading in that cylinder area between the chamber and the throat. It's just in that last .10 or.15" of the cylinder, no leading of the throat. I was using 357 mag cases with the Lyman 358477 and the Lee 358158FN sized .358 with CR lube and backed with 4.4 gr of 231. Shot 45 rounds of each. I wanted a light practice load and these were accurate without any barrel leading. I don't think 358477 was the cause of the chamber leading because the front band extends into the throat; I think the Lee was seated too short in relation to the throat that blowback deposited slight bits of lead in the cylinder and possibly the case mouth did not seal due to the light load. I searched for some similar posts but only found ones like Murphys back in 2006 about throat leading. .357 size CB's are a very snug fit in the throats, .358 size will not enter at all. I use a lot of these CB's (all cast from 2%T, 3%A) in other 357 Mag without this effect. I am going to seat the Lee CB longer, test fire, then up the powder a little and test fire to see what happens. It was really tough to get the leading out and I don't want to have to do it again. Comments would be appreciated.

[runfiverun]

a couple of things could be going on.
rough spots.
the case opening upon firing and gas blowing past the shorter boolit.
tight spots in the cylinder.
just a plain ol pressure mis-match.

[seaboltm]

Slug the cylinders. I would bet they are undersized. Most people shoot j-word bullets, where cylinder size is not as critical as with cast. For lead removal in a cylinder (not a barrel) wrap bronze wool around a nylon cleaning brush. Attach brush/bronze assembly to a drill. Maybe use a bit of Hoppe's No 9. Let'er rip potato chip! In a matter of seconds there will be no lead. Make sure you use bronze wool, which is available from Brownells. $8 worth will last you a lifetime. Steel wool will damage your gun. Bronze wool in the barrel works great, just don't use the drill trick due to the rifling.

[Cherokee]

seaboltm - I used copper wool (not steel) on a bore brush and got most by hand, did not use a drill, and that took a lot of scrubbing; it was really stuborn.

Loaded up 45 rounds @ 1.601" OAL (.058" longer than first batch) to test. If that doesn't work, I will increase the charge of 231.

[seaboltm]

You can hit a cylinder with a drill for 15 seconds and get the cleaning effect that would take you 15 minutes by hand. Especially if the wool is tight fit. You can use a tighter fit with the drill as you aren't doing the work.

[Cherokee]

I test fired 45 rounds today loaded to 1.601" OAL. Afterwards, I checked the chambers and there was lead buildup again. My off-hand groups were not as good either but that was probably me. Cleaned the chambers again. Next I will try bumping up the charge and see what happens.

[OuchHot!]

I eventually came to the conclusion that whatever boolit I used in a revolver, had to have a shoulder that entered the cylinder throat and fit it when the cartridge was chambered. Then most of those problems went away. Obviously in some short cylinders this means a short nosed boolit.

[gray wolf]

Don't know if it will help any but here is a down hill story about cylinder leading that got turned around.
My SBH Hunter 44 mag. was one helll of an accurate pistol. But no matter what I tried the cylinders would pack with lead right after the case mouth at the beginning of the cylinder throat. ( the lead into the throat ) The actual throats would get a light smearing of lead. The barrel was always lead free. The throats were .432 and my bullets were sized for a slight snap through fit with a little thumb pressure. I tried a few different powders from mild loads with 6 grains of tite group ( extremely accurate )
up to 19 grains of 2400, also accurate. Two different bullet styles, Powder puff or screamers they all leaded the beginning of the cylinder throats in all 6 holes.
If I placed an empty case in a chamber the end of the case was way short of the throats, With a loaded round and a bullet with a .100 front band the front band was still .050 short of reaching the beginning of the throats.
The pistol was plagued with some other mechanical problems and went back and forth to Ruger a few times with the above problem never being addressed. The forum showed me overwhelming help trying to solve the problem to no avail.
Ruger offered me a new pistol of my choice, They didn't have a Red hawk so they sent me a SRH as a replacement.
I have been smiling ever since. I had loaded rounds left over from the SBHH and shot them in the new pistol, same bullet, same powder, same everything. NO LEADING anyplace. Bottom line for me was the first pistol had the cylinders cut wrong.
I don't think Elmer Keith could have solved the problem. The cylinders was mechanically geometrically cut wrong.
I don't Water drop the bullets, and they are plain WW some are a little of this and a little of that.
My thread about this went on for pages, complete with pictures. This may or may not help, I hope it does.
The only problem I see is I think you said your bullets were snugged up into the throats.
My thoughts are that if we follow a few simple rules, shooting lead bullets should be fun, not an exercise in hair pulling.
I also understand that at times we may just miss a small detail. But most of the times the guys will pick up on it and advise corrective actions.
BUT ! there are times we must stop chasing the elusive Rabbit down his never ending holes that lead us into the magical land of confusion. Take a breath, step back and look at the problem from a different corner of the room.

[R.M.]

Any soot on the fired cases?

[tward]

Just for information bronze wool is also available in boating stores. Tim

[Mal Paso]

How big are the Chambers in diameter?

[44man]

Boolits too soft.

[detox]

In my new 686 I have experienced leading in that cylinder area between the chamber and the throat. It's just in that last .10 or.15" of the cylinder, no leading of the throat. I was using 357 mag cases with the Lyman 358477 and the Lee 358158FN sized .358 with CR lube and backed with 4.4 gr of 231. Shot 45 rounds of each. I wanted a light practice load and these were accurate without any barrel leading. I don't think 358477 was the cause of the chamber leading because the front band extends into the throat; I think the Lee was seated too short in relation to the throat that blowback deposited slight bits of lead in the cylinder and possibly the case mouth did not seal due to the light load. I searched for some similar posts but only found ones like Murphys back in 2006 about throat leading. .357 size CB's are a very snug fit in the throats, .358 size will not enter at all. I use a lot of these CB's (all cast from 2%T, 3%A) in other 357 Mag without this effect. I am going to seat the Lee CB longer, test fire, then up the powder a little and test fire to see what happens. It was really tough to get the leading out and I don't want to have to do it again. Comments would be appreciated.

My 686 leads in the same area with plain base bullets...yet barrel has no lead. I have tried most everything including powders, alloys (20/1,#2) and different bullets. All bullets were sized to .3750. Next I will try using a different lube such as LBT Soft Blue.

Have you tried using a gas check bullet? I plan on trying some real soon. This protects bullet's lead base from beeing burned and blasted off into cylinder (area between cylinder's forcing cone and case mouth edge).

I believe most all revolvers lead in this area, but it is very difficult to see in this location without using a bore scope. I remove the minor leading using cordless drill, Hoppe's #9 and oversize bore brush.

[detox]

Using my bore scope i examined the cylinders of my 686 against my Blackhawk. The 686 has a sharp edge before forcing cone with a gap of about .020" between case mouth and chambers sharp edge. Maybe this sharp edge is shaving lead? The Blackhawk has no sharp edge with smoother transition. I never noticed leading in this area of Blackhawk cylinder.

Here is diagram i tried to draw. Maybe our 686 guns need to be sent back to S&W to be modified to shoot cast.

[Mal Paso]

Unless the step is over.010 it wouldn't make a difference as brass is that thick.

The trouble removing the lead makes me think gas cutting.

How big are the chambers?

[detox]

Unless the step is over.010 it wouldn't make a difference as brass is that thick.

The trouble removing the lead makes me think gas cutting.

How big are the chambers?

My chambers measure .3810", cylinder throats measures .3570". I used a telescoping gauge and micrometer to take measurement.

Leading still occurs with slightly larger bullets of .3575. So why would you say gas cutting? Should i try a larger diameter of .358 just like original poster did?

[detox]

After reading the Lee reloading manual it appears that my bullet alloy is weaker than PSI generated from powder charge. I believe that if i size to larger .358 diameter along with using a harder alloy such as Linotype or water quenching the bullets my problem may go away. Or i can reduce powder charge (psi) and velocity to match softer bullet alloy. If this does not work its back to the drawing board.

[gefiltephish]

This doesn't solve your problem but it may just make life a bit easier. At the end of a session, I fire 2 gc'd 357's through each of our 686's which leaves them as clean as can be. Well, I do get some lead deposits and carbon on the cylinder face and frame, so I have to manually clean that.

[Mal Paso]

My chambers measure .3810", cylinder throats measures .3570". I used a telescoping gauge and micrometer to take measurement.

Leading still occurs with slightly larger bullets of .3575. So why would you say gas cutting? Should i try a larger diameter of .358 just like original poster did?

SAAMI Spec is .3809" at the breach and .380" next to the throat so that looks good.

This problem comes up a couple times a year and no one had nailed it yet.

I have an S&W 629 that proves gas cutting. The alloy deposited by gas cutting is bonded to the gun metal unlike something that has been scraped off.

There seems to be a threshold gas speed above which there is enough convection to remove metal.

I would reduce the gap between the boolit and the case during firing. Larger Boolit.

[BD]

I think Gray Wolf nailed it. Your cylinders are bored a bit long, and the gap between the end of the case, and the beginning of the throat is leading. SWCs will make this very apparent. My answer to this has always been a RNFP sized and seated out to fill the start of the throat. It will still lead in that short gap somewhat, but it won't effect accuracy, and the lead won't build up much over a couple 100 rounds.
BD

[bones37]

I had the exact same problem with two different late-production revolvers, a Smith 629-6 and a New model Ruger SBH. Graywolf and I had several threads about this, and He and I discussed this problem in several conversations. I agree with Him that the cylinder chambers may be cut 'wrong' for lead boolits, or at least that is what it sounds like to me... Let me explain.

The Smith was bought new in 2008, and from the start it leaded in the cylinder throats NO matter what I did. Different lubes, alloy, powders, water quenching, etc. and still it leaded that same area of the throat. No lead anywhere else. Period. I still thought that it was something I was doing wrong until I shot a friends 629-5. Using the SAME EXACT ammunition that I had cast and loaded in the friends gun, I realized that something was wrong with mine. I examined the friends gun, and not a trace of lead could be found from the cylinder to the muzzle. During the comparison of both revolvers I could SEE the pronounced step in the area just forward of the chamber, while the other had a seamless gradual transition. DETOX nailed it with the diagram exactly. My experience with the Ruger was an exact carbon copy of the Smith, except I didn't have the other issues that Graywolf had. I've since replaced the Ruger AND the Smith with two older Smiths, a 29-3 and a 29-5, both of which are lead free, again using the same cartridges.

bones.

[Cherokee]

detox - your #14 post nailed the shape of the chambers in my 686 5". I can easily see the step in each chamber. I may have resolved/lessened the problem with the Lee 358158FN with longer OAL and more powder, but need to test what happens with 358477 and some others. One of the things that makes reloading interesting.

To answer some questions raised in other posts: No soot on the cases; did not measure chambers; will not add to the cost of reloads by using gas checks, gun will go first.

[detox]

Looking from the breach end of cylinders using my Hawkeye borescope step appears to be less than 005" high, but varies from .000 to .005 (not being concentric). This is less than my case wall thickness measurement of .010". Cylinder charge holes are not perfect, but IMO close enough for cast.

I did a Google search on cylinder leading and lots of people have this same problem...even in some Rugers.

[cbrick]

my Hawkeye borescope

Question . . . Did you get the new LED light for your Hawkeye? I have always loved my borescope, even tells ya stuff ya probably don't want to know but have also been kinda disappointed with the amount of light and battery life. Couple of months ago I got their new LED light for it. WOW! Unbelievable difference, several times the amount of light and it's white light making everything much clearer & sharper. Well worth it in my opinion.

:hijack: Back to the topic at hand.

Rick

[detox]

I purchased my Hawkeye several years ago...1997 maybe...so it does not have the LED light. It uses just the standard Brinkman Mini flash light. Although it does have the 90 degree mirror option.

I purchased my 686 about 1 year before i purchased the Hawkeye.

[cbrick]

After the Brinkman they used Mini Mag. Here's a link to Gradient Lens lighting options just in case your interested.

Lighting Accessories (http://www.gradientlens.com/LightingAccessories/Lighting.aspx)

Rick

[detox]

Mine has the Mini-Mag (i got the name wrong). The Hawkeye is a wonderful tool to have if you really love guns. I have used it to inspect crowns, chambers, leads, bores, revolver chambers and how well revolver throat lines up to barrel etc. My most accurate rifle (Remington Model 700 VS chambered in 223 Remington) was carefully inspected before buying. Gun shoots 1/4" groups on regular basis with cheap Tasco 30 power target scope. The next revolver i buy will also be inspected carefully using the Hawkeye.

[Wally]

I shoot .38 and .44 Specials in magnum revolver cylinders. You get a gunk buildup in them. I use a Tenex nylon brush with Chore Boy strands wrapped around, it and spin in a drill. I have an adapter that chucks into the drill and then you can screw the brush onto it (some use a cut off end of an old Outers cleaning rod) . I do not use any liquid bore cleaner...takes a few seconds. have read others use 0000 steel wool...I am sure it is fine, but you get a mess from the steel wool particles that break off in the process.

[detox]

I cured my cylinder leading problem by sizing bullets larger using .358 sizing die and changing lubes. My 686 throats measure .3575 and the larger .3585 bullets seem to help. Lately I have been using LBT Soft Blue and Lyman Moly Lube with better results.

[cbrick]

I purchased my Hawkeye several years ago...1997 maybe...so it does not have the LED light. It uses just the standard Brinkman Mini flash light. Although it does have the 90 degree mirror option.

I remembered talking about this and had to dig out this thread.

I paid Gradient Lens $95 plus shipping for the new LED light they have for the borescope. I gotta say that I really love it, a tremendous improvement over the Mini-Mag light but (there's always a but huh?) now I am a little bit sick over spending over $100 for this light.

Lowes sells a LED conversion for the Mini-Mag and it slips right on in place of the original lens and bulb holder. Works like a champ which is why I'm a bit sick over it . . .

It sells for $7.95. :groner: :holysheep

There ya go if ya want a huge step up for the borescope without taking a second out on the house. I had recommended the Gradient Lens LED to goodsteel for his brand new borescope so before he went and spent $100 on it I bought him the Lowes replacement LED and he says it fits on the scope and works perfectly.

Rick