View Full Version : How much lead fouling is too much?

Dodge DeBoulet
February 17, 2010, 04:33 PM
I shoot mostly Missouri Bullet Company cast lead bullets from my S&W M&P .40 Full Size. When I get back from the range, I've usually fired anywhere from 200 to 300 rounds.

I clean after every shoot, and examining the lands and grooves of the barrel will often find patches or streaks of lead in the grooves. There's still plenty of bare steel showing, but there are some bumps and other irregularities caused by the lead. They can actually be felt using a small probe.

Brushing, soaking, scrubbing, etc. with conventional handgun cleaning tools and solvents doesn't get it out. The only option I've found that works is to scrub with a piece of "Chore Boy" copper pot scrubber rigged to the end of my cleaning rod. This gets the lead out very nicely and leaves the barrel looking practically brand-new.

The question is, though, whether it's really necessary to scrub everything out before using the gun the next time. Will the lead deposits in the grooves have any measurable effect on accuracy? Am I being too anal about cleaning my gun?

Thanks . . .

February 17, 2010, 04:40 PM
Leading will affect accuracy.
Have you tried to run a patch in the bore soaked with Hoppes #9 or your cleaner and let it sit overnite? Of Course after the initial cleaning. You may need gas checks and lube on the bullets your using. You can fix most of the leading problem.

February 17, 2010, 04:54 PM
Severe leading changes point of impact, probably accuracy too.

I had a case of 32 S&W Long Aquila ammo. Aquila ammo has soft bullets that leaded something awful in this prewar S&W . I shot until I could not see the rifling anymore. Then I shot the lead out with jacketed bullets.

The point of impact changed drastically from clean barrel to fouled barrel and back again.

I always finish up a range session shooting jacketed through my handguns. Scraps out the lead and makes cleaning easier.


February 17, 2010, 07:21 PM
I`ve posted this before but as always I`m ready to help !!

wet the bore with your favorite solvent ( I use eds red) let soak while ya wrap ALL copper pot scrubber around an old brush ,enuff to make it tite fittin!!
make slow deliberate passes & in a few the ledbegone!!!!!!:cool:

Try backin off on the taper crimp die a bit , there famous for "resizin" a lead bullet in the case.

Slamfire ,I`ve seen cases & primers blown "shootin" the lead out!!! pressures go way up!!!!


February 17, 2010, 07:26 PM
GPman is right on. I would definately be careful shooting jacketed bullets to "clean" out the bore. I have heard that this can be potentially dangerous, especially if the grooves are completely filled with lead. Be careful!

Dodge DeBoulet
February 17, 2010, 08:02 PM
Severe leading changes point of impact, probably accuracy too.

So what is severe leading? Is that when there's so much lead in the barrel that you can't distinguish the lands from the grooves, or some point less than that? Are the patches and streaks of lead I see in my bore just "light" leading?

I guess I need to know where to draw the line, and at what point leading will significantly affect accuracy.

February 17, 2010, 08:59 PM
There is no rule set in stone that says when the lead gets "this" bad, your accuracy will deteriorate. You accuracy will deteriorate when you can't hit the bullseye. ;) Some barrels will tolerate more or less leading than others. I have even heard of guys saying that they get their best accuracy with a little bit of leading in the barrel. As far as how much leading is too much....well, lead bullets swage down fairly easily, so I can't see a real problem with too much leading. Jacketed bullets, on the other hand, do not swage down as easily and this is why the pressure can spike. As far as running lead on top of lead, I don't see any problems with that. I personally like to clean my guns after every range trip, as everyne should. Now, say you are shooting 38 spl lead bullets and decide to switch over to 357 mag. You will want to make sure that the cylider throats are clear of ALL leading. If here is leading in the cylinder, a 357 mag round (which is longer) may be a little harder to get in the cylinder. This is a red flag that you need to de-lead your cylinder. If you ignore this red flag and jam the round in and fire it, the initial pressure can be raised drastically because the mouth of the brass will be pinched (from the leading left in the cylinder) and more pressure will have to build up to push the bullet out of the case. Can be a bad deal. As far as cleaning your gun completely after use with lead bullets...absolutely. Any residual lead in the barrel can lead to leading on your next range session. The lead left in the barrel can peel lead off of bullets fired later on.

February 18, 2010, 11:36 PM
I see 2 kinds of leading !!

1- is the smeared mess from 1 end to the other , plain rite out undersized bullet fit GAS CUTTING the bullet & poor accuracy from the get go!!

2- is the "strings" of lead caught on the grabbin edge of the barrel grooves,this is from the alloy not being able to grab & spin the bullet ( over speedin) & if bad enuff will lead to gas cuttin.
The strippin on the other hand most of the time push out with a snug jag& patch!!

I have shot lead bullet loads that I knew would`nt lead the barrel thru a leaded barrel & removed most of it , but never again a jacketed!!!

February 20, 2010, 07:50 PM
I've seen build up of as little as half a thousandth cause leading to begin to grow rapidly. That is, the constriction narrows the bore enough that it resizes the lead bullet, which then undergoes tipping and gas bypass issues as it travels further down the tube. In a self-loader, the problem is commonly exacerbated by bullets seated too deeply in cases that are too short to headspace on the case mouth. Instead these loads headspace on the extractor hook. It is a very common condition in the 1911. That biases the cartridge to one side of the chamber at firing and increases both gas bypass and lead shaving at the mouth of the throat. Both promote leading.

The first cure to try is headspacing on the bullet, if your magazine will feed bullets that long? Remove the barrel to use as a gauge. Seat the bullets out far enough that when you drop one in the chamber it is flush with the back of the barrel. I've had this practice reduce leading to something that may be ignored and reduce group size up to 40%.

A second thing to look at is bullet size. Slug your bore. You want lead bullets to be at least 0.001" bigger than your actual groove diameter. Some guns work best with them 0.002" over actual groove diameter. You want to know you are getting the right size for your gun.

You can firelap the bore to polish it and the throat if it isn't already smooth.

You can treat the bore with a lubricant that survives firing temperatures and pressures. The two I'm familiar with are Shooters Solutions MolyFusion and Sprinco's Plate+ Silver. The former is applied to the warmed barrel with a bore mop, and leaves the bore slightly darkened and waxy feeling. The latter is applied by plugging the bore muzzle and filling it to the chamber throat and letting it sit three days.


February 21, 2010, 07:34 AM
Just curious, why the all copper wrap to remove leading? I've had no trouble over teh years using the brass brush and Hoppes #9 to get the lead out. Just put the tip of the barrell in the cup of solvent and scrub like hell and it comes clean eventually. Is the copper doing something besides scrubbing? Some chemical action maybe?

February 21, 2010, 09:44 AM
Trip, the copper chore boy strands wrapped around a cleaning brush and pushed thru the barrel will clean it 10x faster. It makes a much tighter filt and works to peel the lead from the barrel. When you wrap the strand around your brush, you want to make sure that it fits the barrel with a very snug fits. Sometimes the bristles on the cleaning rod are not stiff enough to get the lead out quickly. Trust me, it works and you won't be disappointed. ;) Just make sure you get the COPPER chore boys.

February 21, 2010, 11:12 AM
I always finish up a range session shooting jacketed through my handguns. Scraps out the lead and makes cleaning easier.

I have been told by a few Armor's at different gun matches to never shoot FMJ after lead until you clean the barrel. It can cause a lot of problems.

February 21, 2010, 06:18 PM


Now , I take a straw & dip in my containers , never a brush or patch !!

It keeps my chemicals fresh to the last drop!!!:cool:

February 22, 2010, 04:08 AM
Here, friend, is the answer:

The bullets you are using are too hard for your application.

You see, when the charge gets ignited, the bullet should be able to obturate--swage outward--to fit the bore. This gives a good seal.

Hard bullets often fail to do so at handgun pressures, and will allow hot gasses to fly past the bullet as it travels down the bore. This will actually allow the bullet to "plate" lead into the bore.

The solution? Use a softer bullet for your handgun shooting.

I have been casting bullets for years, and have found that straight wheelweights are an excellent choice for most pistol and revolver bullets. I use bullets cast from wheelweight in .38, .45 ACP, .44 Magnum and .45 Colt. I always size one-thousandth over bore diameter; example: my .44 bullets are 250 grain Keith type semiwadcutters, sized to .430 (bore diameter is .429). I have loaded them soft (small charges of Bullseye and HP38), medium (8.5 of Unique, my favorite midrange load) and fast (hefty charges of W296 and H110). Absolutely no leading.

I have also used Hornady swaged bullets; these are dead soft lead in my handguns with absolutely no leading.

Now, hard cast bullets DO have their place--these would be heavy loads in big bore revolvers, such as the .44's and above. But, in the medium calibers, they will allow flame cutting. Hope this helps!

Uncle Buck
February 22, 2010, 07:41 AM
Powderman has a very good point. go to this site and using their formula, determine what bullet to buy/order. I had this problem with my .45LC and after I read the article, I changed the bullet. Very little leading now.


Dodge DeBoulet
February 22, 2010, 07:46 AM
If (lack of) obturation is the issue, wouldn't you get the same effect if you were using a smaller powder load than is really needed?

I've stayed at minimum recommended loads because I prefer the lighter recoil for target practice, but if the leading issue is caused by the failure of the bullet to obturate, it seems that there's more than one possible reason.

I'm using Missouri bullets with a BHN of 18.

February 22, 2010, 01:36 PM
slug the bore , ream the throats .001 larger & put a taylor cut on the forcin cone , optimized for lead bullet shootin!!!!

Then get bullets as large as the cyl will let ya chamber , alot easier going down than up in size.

Or get ya some isotope lead & tuffen it up with a little tin , as it`ll stay around 11 bhn. works real good at 16,000psi

February 22, 2010, 07:54 PM
I've stayed at minimum recommended loads because I prefer the lighter recoil for target practice, but if the leading issue is caused by the failure of the bullet to obturate, it seems that there's more than one possible reason.

Bumping up your charge may be enough to obturate your bore with those harder bullets. If you want lighter recoil, then you need a softer alloy.