Pb Pb Pb

[Nick_C_S]

Okay, so I shot IDPA today. Had fun. Always do.

Today, I shot 80 rounds through my trusty S&W 686 4". When I got home to clean it, I found my gun had the holy schnitzky leaded out of it. It was awful.

The first 1 1/2" of the barrel breech was leaded up pretty good - I kind of expected that. What I didn't expect was the lead encrusting the forcing cone area; lead splattered up on the top strap; and copious quantities of lead deposited on about the last 1/4" of the cylinder charge holes!! If you can imagine. I've never seen that before.

For some background: I rarely shoot lead in this kind of quantity. And when I do shoot lead, I often back them up with jacketed bullets to clean out the lead every so often during the shoot. Well, another FL forum string was telling me that shooting jacketed bullets don't really clean out the barrel. Yeah, right. Today's shoot blew that theory clean out of the water. Lo and behold, I've been doing it right for the last 30 years.

But I digress:

This was also the first time I've shot lead bullets this soft. They're Missouri Bullet Co. PPC #2. 148g DEWC BNH 10 (soft). Great shooting bullet. I want to get more. But I'm a little concerned about all the lead.

148g DEWC. 3.2g Bullseye. Win WSP primer. This is a 38 Special load (duh). I haven't put it to the chronograph yet, but I'd guestimate it to be in the 750 - 800 fps neighborhood. Should be a good match target round (it was) with minimal leading (it definitely wasn't).

Anybody care to chime in and tell me what I did wrong? (Besides not ending my day with jacketed bullets - like I normally do.)

[jepp2]

You have a fit problem.

A good reference to start can be found here.

You did thoroughly clean all the copper out of the barrel before you shot the lead, right? I mean all the copper out, not just a quick pass and thought it was clean.

[pete2]

Try some hard cast 158 RN or some Speer 158 RN. Both will help on your reload time and I don't get much leading with either bullet even the soft Speer doesn't lead much. You may have another problem. I shoot lead in a 15, a 586, a 19 and a 686.

[Axelwik]

Slug the bore, use bullets that are correctly sized, then never have to deal with a mess that bad again. Also don't try to push plain-base bullets to wharp speeds. If you need magnum velocities use a bullet with a gas check.

Bronze wool wrapped around an old bore brush will remove the leading. Make sure it's really bronze and it's a tight fit; don't use the copper-plated steel scrub pads from the grocery store or you'll ruin the bore.

[JohnKSa]

Well, another FL forum string was telling me that shooting jacketed bullets don't really clean out the barrel.

Whether they do or don't, it's a dangerous practice that can damage the gun if there's sufficient lead buildup.

At least one manufacturer recommends against it stating it should NEVER (their emphasis) be done, and Allan Jones (20 years with CCI Speer during which he held the positions: Head Ballistician, Technical Specialist, Manager Technical Publications, CCI-Speer Operations, Author and Editor of Speer Reloading Manuals 12-14. 16 years experience as a forensic firearms examiner in the Dallas County, Texas Crime Lab.) states that he has seen several guns damaged by the practice.

Here's a post by a THR member who has seen barrels damaged by the practice.

http://www.thehighroad.org/showpost....2&postcount=14

[Nick_C_S]

Slug the bore, use bullets that are correctly sized, then never have to deal with a mess that bad again. Also don't try to push plain-base bullets to wharp speeds.

I started with a clean, shiny barrel, that had a very light coating of Break Free CLP in it - as always. I always start with a clean gun (although it looks like I won't next time - given all the lead lol).

What is meant by "slug the bore?"

The bullet diameter is .358 - same as all the other ones I've used for years; decades, actually.

I loaded a very mild target load for these - 3.2g Bullseye. I have a hard cast 148g DEWC that's 18 BHN for my "hotter" wadcutters. For those, I use 4.2g of W231, and they chrono at 963. I have virtually no leading problems with them, btw.

When I want to go faster than that, I just move to a jacketed bullet.

[jepp2]

What is meant by "slug the bore?"

Slugging the bore is driving a pure lead oversize bullet through the barrel. Then you can determine the groove diameter of your barrel. Normally you would select a bullet at least 0.001" greater than the groove diameter.

However your S&W will have 5 lands and grooves and the accurate way to measure that slug is with a V groove micrometer.

But you can just take the slug that you just passed through the barrel and check the cylinder throats with it to make sure the throats aren't smaller than the groove diameter of the barrel. This slug should pass through the throats with just finger pressure.

Take one of your new bullets and see if it will pass through the throats with finger pressure. It it will not, then the throats are reducing the bullet diameter.

But if you don't know what slugging the barrel is, you might want to know more before you do it.

[Nick_C_S]

BTW, I got the barrel almost entirely clean, except for one little spot near the breech. Wasn't easy. The remaining lead is mostly in the front of the cylinder charge holes. I'm sure I could get them all cleaned out (and the little remaining spot on the bore) eventually. But we had a lot of stuff going on around the house today, and didn't plan on the needed extra time to clean my gun. So basically, the gun's pretty clean right now.

My primary concern, and purpose of the original post is why did this round lay down so much lead in the first place? I guess I'll take them out and chrono them soon; but I already know there will be no surprises (750 - 800 fps). I've been shooting this gun since 1986. I know the strength of a round from this gun, just by feel. To be certain, the round is not too hot. It's a wimpy round.

[Nick_C_S]

Thanks jepp2. That was informative. And for the V-groove micrometer: I am very familiar with them. In a past life - so to speak - I used them on a daily basis to measure +/- .0001".

I can't imagine however, my Smith 686 "slugging" any different than the other umpteen-million of the same model that they have produced.

I am going to check those bullets in the cylinder throats right now though

[Nick_C_S]

Hmm. Learn something every day: Every bullet I try (3) has an interference fit with the cylinder throats with two different guns. I never knew that. I just always assumed there was a few thousandths clearance. Inconclusive relative to this string; but interesting to know, none-the-less.

[noylj]

All of those Umpteen million guns were bored with a "tool" (can't think of the name) that may or may not be the exact same size and may or not have been worn. Believe me, S&W and all the others have produced some real weird dimensioned guns at times.
SAAMI specifies a groove diameter of 0.355 +0.004/-0.000". The cylinder throat is supposed to be 0.358 +0.004/-0.000", but I have seen them much smaller.
Your gun is NOT like any ones else's and has its very own assorted chamber dimensions that, hopefully, still fall within SAAMI specs, but could still not meet the needs for shooting lead bullets.
When it comes to wadcutters, I have only shot flush-seated and the bullets were 0.360".
Next, unless you are using a properly sized expander plug that will bring the case ID back to 0.356-0.357", you may well be swaging the bullet diameter down. Pull a seated bullet and measure its post-seating diameter.
Next, wadcutters are not designed for high speed/high pressure.
ANY throat/bullet clearance is an opening for gas cutting--which will show up on the forcing cone and, possibly, the throat itself. Seeing that leading means the bullet is too small. A hard bullet will not obdurate (expand) to fill the throat/groove and you get excessive leading. Shooting lead is a matter of the right bullet fit and the right alloy.

[Nick_C_S]

Pretty awesome string.

Yes, guns may be made by machines; but they're made by machines being run by people. No two are alike, I suppose.

[FrankenMauser]

Your wadcutters are under-sized, and allowing massive amounts of blow-by.
Missouri sizes those bullets to .357" for use in match barrels. In your revolver, which clearly seems to be .358" or larger, that's no good. Generally, the "minimum" recommended size is .359".

Also...
BHN 10 is not "soft" by cast bullet standards. It's just "soft" by commercial bullet standards. BHN 10 is actually harder than needed for 800-900 fps.


Bottom line:
It's a sizing issue. Get a bigger bullet.

[Geezerbiker]

While you're figuring out the problem, mix up some Ed's Red bore cleaner to get the lead out...

Tony

[Mike / Tx]

Nick,

Just going out on a limb here as I found this to be the case with some of my own cast loads, but do your fired cases still have some or most the crimp still in place?

I had that happen to me with some light loads I made up for my pop's Colt Army 38 SPl. I didn't want to load them too warm so I was using about the same type load you were with some range lead cast DEWC's. What I found was that the loads simply didn't have enough pressure to push the crimp out, which in turn actually shaved the WC's as they came out making them undersized. It wasn't by much but enough that it caused leading. I bumped the load up a half a grain or so more and everything shot just fine.

As for the 10 BHN thing, I shoot for around that hardness with most of my alloys. Usually it will come out a bit more at around a 12 at most, but sometimes down around a 9 as well. Either way they are being shot at up to around 1100 fps out of my 357, 41, 44 and 45 Colt. Oh and yes I did find that the 9 to 11'ish was way too soft for anything higher than that. It only took 4 rounds to realize it too.

[flashhole]

Nothing to add but there is some good info in this thread and I want to follow it. Good luck sleuthing the problem.

[Unclenick]

Nick,

The cure may be as simple as switching to .357 Mag brass and upping your charge weight to 3.5 grains or maybe even as high as 3.8 grains. What you have, as others have already described, is an unfortunate combination of a fit problem that is leaking enough gas forward around the bullet and perhaps also backward around inadequately expanded brass that it can't build enough pressure to upset the bullet to obturate¹ the chamber throats and bore afterward. The reason for changing the case to the longer .357 Mag case is so the bullet doesn't have to jump the extra 0.135" through a part of the chamber that is wide enough for a loaded case, giving more opportunity for gas cutting and blasting lead onto the chamber walls. The greater powder charge will cause the brass to seal the chamber better and will upset the bullet better.

Once that lead mist is being blown off by the gas cutting, it's no surprise that your cylinder face and top strap get heavy lead deposits as the mist and gas vent at the barrel/cylinder gap. I once made a front sight extension for a .22 Target version Ruger pistol. Even with the very high .22 Long Rifle expansion ratio (meaning you get low muzzle pressure), the underside of that sight where it overhangs the muzzle builds up an impressive cake of lead after awhile. That lead is softer than yours, but the softer the lead, the more easily it is cut by gas blasting it off, so your BHN 10 bullets will gas cut more easily than BHN 16 bullets do. Also, you're taking the maker's word that they are actually BHN 10. It's pretty easy for a BHN measurement to be off 20%.

Just to be sure we are discussing the same things, I think what you are calling charge holes are chambers and the cylinder in front of these charge holes is the cylinder face. Not trying to pick on your terminology, but I want to be sure were not talking about something different. SAAMI has a good Glossary of terminology near the bottom of this page, and where there is an uncertain usage, you can look it up.

Keep in mind what JohnKSa said about the hazards of firing jacketed bullets into heavy lead deposits. Lone Wolf has made a whole business of standard rifling replacements for polygonal pistol barrels because polygonal bores can quickly build lead deposits until pressure blows out case heads or even bulges the barrel. And that's just pressure from additional lead bullets, much less firing a higher pressure jacketed load through it.

Also keep in mind the scientific principle of independence of variables. When you change two variables at once, you can't prove which one is responsible for what. In this case you both stopped shooting jacketed "cleaning" loads and you went to a softer bullet alloy than you had used previously. Since softer bullets can lead to heavier lead deposits, you can't know jacketed loads will behave the same way they did with your old lead deposits, nor that failing to shoot jacketed bullets bears any responsibility for the extreme leading you have. You may find the jacketed load pressure safety margin is much diminished by these heavier lead deposits. It's better not to tempt fate in this regard.

A couple of things to check: Slug your bore and each of your chamber throats and measure the diameters. If the chamber diameters are not all the same, you can get them reamed. Reaming chambers uniformly to SAAMI maximum with a sharp reamer is the first step a revolver smith takes to accurize a revolver. The reason is that nothing messes with revolver accuracy more or causes lead to accumulate faster than bullets that are swaged down through a chamber throat narrower than the barrel groove diameter. The other way around promotes accuracy by avoiding seal failures anywhere along the bullet's path to the muzzle. As long as diameters keep getting narrower, a good seal is maintained. A bore that tapers down slightly as it approaches the muzzle is desirable with lead bullets, in particular, for this reason. It's why pre-war revolver target shooters were known to rebarrel S&W revolvers with Colt barrels. Thet liked the Smith action better for tuning, but the Colt barrels had tapers where the Smith barrels were straight.

These days, Flex Hone makes chamber hones that can be used to uniform throats. They demonstrate this in one of their YouTube videos. The hones are cheaper and simpler to use than a reamer.

When slugging the bore, you want to run a lightly oiled patch through it first. The thin oil layer in the bore helps you feel for tight spots by reducing the grab of surface imperfections. When you push a slug into the muzzle and slowly push it down the bore, it is not uncommon to discover the bore has a constriction where the barrel screws into the frame due to excessively tight threads. If the constriction is bad enough, it needs to be removed by hand lapping or by firelapping, as it can make a bullet unable to obturate the bore beyond the constriction, and a wide place following a tight place can allow the bullet to cock slightly and become unbalanced by impressing the lands into it unevenly, front to back.

You can buy slugging supplies and kits (NECO, Beartooth Bulliets, Missouri Bullets, etc.). I use Hornady pure lead round balls for most slugging these days. Pure lead is important because casting alloys are springy enough to fail to reflect diameters accurately and are also harder to push down a tube. I take a lead ball that is a little oversize and roll it between steel plates until it is just two to five thousandths over groove diameter. I oil it and run the lightly oiled patch down the bore, then tap the slug into the muzzle using a brass or wood dowel and a plastic mallet. Once it is started in at the muzzle, I push it through with a brass rod or with a cleaning rod, feeling for bore uniformity and bore surface condition all the way down. With practice, you can feel a lot. Bill Calfee says he can slug .22 barrel blanks with a pulled lead bullet and feel which end of the blank should become the muzzle (the tighter end), even on a custom lapped blank, which you'd think would be pretty uniform.

For cylinder chambers I remove the cylinder from the gun so I'm not asking the crane to put up with hammering. I have a plastic block the cylinder face rests on while I tap the slug in from the breech end and get it firmly in the throat before pushing it out to measure it. Again, a lightly oiled patch goes through first and the slug is lightly oiled. These slugs are measured and irregularities are identified.

Many get bullets sized to their revolver chamber throats, finding it most accurate (provided the throats are bigger than the groove diameter of their bore). Bullets at 0.002" over groove diameter (.359" for you) often prove more accurate than the standard 0.001" over groove, if they chamber OK. Check that your cast bullets are really round if they are dragging in the chamber throats now. Despite being sized, some can be slightly out of round if the mold wasn't closing perfectly. The extra thickness on that axis can spring back out slightly after sizing.

Finally, the page on firelapping at the LASC site has a description by a fellow who shoots very light lead loads down the bore of his gun that has some JB Bore Compound left in it. He repeats until it is pressure polished that way, and he swears he gets no leading even with a bore constriction after doing this. It suggests that if you have enough pressure to bump the bullet back up after passing through a constriction, and you have the bore surface smooth enough that it doesn't start shearing lead off on its way through the constriction, you can work with it in place.

Good luck with it.

Nick


¹ "Obturate" is commonly misused in shooting to mean upsetting the bullet. The word has the same root as "obstruct", and it actually means "to seal off", meaning the bore or chamber is obturated by the bullet. The bullet itself is merely upset or "bumped up" until it is fat enough to achieve the seal.

[jim8115]

I have a half dozen 38's and 357's. Loads that will leave the bore as clean and shiny as a mirror in one gun will lead in another.

JIM

[salvadore]

Mr. Mauser is probably right. I've been reloading for 45 years and casting for 41 and the one really helpful thing I've learned is cast to throat size or even a bit larger and if you have a leading problem, a harder alloy probably won't help. I have two OPs one a 32/20 and a .38 spec. that get shot hundreds of times without having to clean the barrels with a brush. A cotton swab brush pushes the unburnt powder and whatever crud out and the barrel is clean. That goes for 3 .44 spec. two .45 Colts. I do have a couple of shooters that have very shallow rifling and a hard cast bullet does help with accuracy and leading. One other thing, I've gone from straight WWs to adding lead to the WWs for a softer alloy. Too late to make a long story short, oh well.

[Nick_C_S]

From FrankenMauser: Your wadcutters are under-sized, and allowing massive amounts of blow-by. Missouri sizes those bullets to .357" for use in match barrels. In your revolver, which clearly seems to be .358" or larger, that's no good. Generally, the "minimum" recommended size is .359".

The .357 bullets from Missouri that you mention are the PPC #1's. I got the PPC #2's - they're .358.

That doesn't mean that my wadcutters are not undersized. But I just wanted to clarify what bullet we're talking about here.

[Nick_C_S]

Lots of good reading there Unclenick. It all makes sense. And yes, by "charge holes," I meant the front of the cylinder (throat).

After this shooting season (when the weather cools) I plan on sending this revolver to S&W to have them work on it. I was going to have them do the "Master Revolver Action Package" on it. I'm not sure if that involves accurizing it. I spoke to them before. And I'll speak to them again before I send it in.

Actually, I'm going to send them another 686 of mine first - I'll be doing that very soon; probably this week. It's a new (I have - maybe - 200 rounds through it) 7-shot, 3" barreled model and the trigger is crap. I'll let them go to work on that one first before I turn them loose on my favorite gun ever.

[zxcvbob]

Start at about 2.5 grains of BE and work your way up, expecting a good load about 2.8 -- you might be too high already at 3.2 grains. How deep are you seating the bullets?

[243winxb]

2.7gr Bullseye.

[pete2]

For cleaning get a chore boy copper pot scrubber. Wrap a piece of it around an old .38 cleaning brush and it will wipe the lead out of the bbl and the chambers in the cylinder. I get more lead in the chambers than in the bbl.

[Unclenick]

Let penetrating oil work for 24 hours before applying a mechanical removal technique. It makes things much easier. Sharpshoot'R's product, No-Lead, makes it even easier by putting the lead metal into an easily patched out compound.

2.7 grains is the old standby for swaged hollow base wadcutters. They are both softer than his bullet and have the skirt that takes very little pressure to upset out to obturate the throats and bore. That's why they are designed that way. A cast bullet made of harder material and possibly a little undersized for his gun may or may not respond similarly. I can use those low loads with my cast Lee Tumble Lube wadcutters, but I shoot them unsized (as-cast) so they are close to .359", which is the other way to handle the sealing issue if you don't have undersized chambers or a bad bore constriction.

The other factor, and another reason I recommended he try .357 Magnum cases, is some primers will push the bullet out of a tight space before the powder can build pressure, thus actually lowering the peak pressure when the initial powder space is small. Take a look at Hodgdon's data for another quick powder, HP38/231, for the 148 grain wadcutter in .38 Special and in .357 Magnum. The latter reaches higher pressure from a smaller charge! When I first saw this I assumed it was an erroneous transposition of data, but an email to Hodgdon confirmed that it is the correct data collected by the ballistic technician. The bullet being started forward by the primer and thus making it hard for the powder to catch the pressure up as expansion continues is the only explanation I've encountered thus far.