Ammunition
Shooting Cast Lead in a Revolver: Fit, Fouling and Cleaning
Leading is almost always a fit problem wearing the costume of a hardness problem. Shooters respond by buying harder bullets, which frequently makes it worse.
The short version
- Fit matters more than hardness. An undersized bullet lets gas past it, and that gas is what strips lead into the bore.
- Harder is not automatically better. A hard bullet that is too small obturates less and can lead worse than a softer one that seals.
- Revolvers add a variable rifles do not have — the cylinder throats. If they are undersized or oversized relative to the bore, leading follows.
- Never use abrasives to remove leading. Chemical and mechanical methods that do not cut steel exist and work.
Why shoot cast lead at all
Cast lead is cheap, it is the traditional revolver projectile, and in a properly fitted load it is accurate — target shooters used it for a century before jacketed bullets became common in handguns, and cast bullet shooting remains a discipline in its own right.
For handloaders it is dramatically cheaper than jacketed, particularly at high volume, and for anyone casting their own it approaches free. Cast bullets are also gentler on barrels than jacketed ones over very high round counts, and they can be driven at moderate velocities that suit revolver cartridges well.
The catch is that cast lead is less forgiving. A jacketed bullet works acceptably in a wide range of barrels. A cast bullet works well when it fits and poorly when it does not, and diagnosing the difference is the skill.
What leading actually is
Leading is lead deposited on the bore surface, usually as streaks or a smeared layer, and typically worst just ahead of the forcing cone and again near the muzzle.
It arrives by two routes. Gas cutting happens when hot propellant gas gets past the bullet instead of staying behind it. That gas is moving fast and is hot enough to melt the surface of the lead, and it strips molten lead off the bullet and plates it onto the bore. Mechanical smearing happens when a bullet is driven faster or harder than its lubricant and alloy can cope with, and lead simply rubs off against the rifling.
Gas cutting is by far the more common of the two in revolvers, and gas gets past a bullet for one main reason: the bullet is not sealing the bore.
| Location | Usual cause |
|---|---|
| Heavy just ahead of the forcing cone | Gas cutting from poor fit, or a rough or eroded cone |
| Streaks the length of the bore | Undersized bullet, or inadequate lubricant for the velocity |
| Concentrated near the muzzle | Bullet stripping at speed, often too fast for the alloy |
| On the cylinder face and forcing cone exterior | Normal blow-by residue, largely cosmetic |
| Sudden onset with a load that was fine | Changed components, or a fouled or damaged bore |
Fit: the variable that matters most
The single most common cast-bullet mistake is treating leading as a hardness problem. Shooters get leading, buy a harder bullet, get worse leading, and conclude cast lead does not work in their gun.
Here is the mechanism. When the powder ignites, pressure upsets the base of a lead bullet outward — obturation — and that expansion is part of how the bullet seals the bore. A softer bullet obturates readily. A very hard bullet resists it. So if the bullet is already slightly undersized, making it harder means it seals less, which lets more gas past, which produces more gas cutting.
The general principle experienced cast shooters work to is that a cast bullet should be at or slightly above bore groove diameter rather than at or below it. A very slightly oversized bullet swages down to fit and seals completely. An undersized one never seals at all.
Bullet diameter as sold and bore dimensions as manufactured both vary. If you are chasing a leading problem, measure the bullets you are actually shooting with a caliper rather than trusting the box, and get the gun’s dimensions established rather than assuming nominal. Almost every long-running leading complaint turns out to be a dimension nobody checked.
Calipers and bore inspection light
- CalipersActual bullet diameter as sold
- LightBore condition and where leading sits
- AlsoCylinder throat and chamber checks
- RuleMeasure, then change one thing
A leading problem is a measurement problem, and guessing at it is how people end up with three boxes of bullets that all lead. A caliper tells you what diameter you are actually shooting rather than what the box claims, and a good bore light tells you where the leading is concentrated, which points directly at the cause. Change one variable at a time after that, not three.
Bottom lineCheap, and it turns a frustrating trial-and-error problem into a solvable one.
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Cylinder throats, the revolver-specific problem
A rifle bullet goes from case to bore. A revolver bullet goes from case, through the cylinder throat, across the barrel-cylinder gap, into the forcing cone, and then into the bore. Each of those transitions is an opportunity to lose the seal, and the throats are the one people overlook.
The cylinder throat is the short section at the front of each chamber that the bullet passes through before it leaves the cylinder. Its diameter relative to the barrel’s groove diameter matters a great deal:
- Throats smaller than groove diameter swage the bullet down before it reaches the barrel. It then arrives undersized, cannot seal, and gas cuts past it. This is a classic and frustrating cause of leading that no change of bullet hardness will fix.
- Throats substantially larger than groove diameter let the bullet tip and enter the forcing cone off-axis, damaging its base and hurting both accuracy and sealing.
- Throats that vary between chambers produce inconsistent results — one or two chambers grouping differently from the rest.
A rough or eroded forcing cone contributes too, shaving lead off bullets as they enter. Both throat and cone issues are gunsmith territory; they are correctable, but not at the bench with a cleaning kit.
Hardness and lubricant
Once fit is right, alloy hardness and lubricant become the fine adjustment.
Broadly, softer alloys suit lower velocities and obturate readily; harder alloys resist deformation at higher velocities but need good fit to work at all. There is no single correct hardness, because the right answer depends on the velocity, the pressure curve and the fit. The sequence that works is: get fit right, then adjust hardness to velocity — never the reverse.
Lubricant is the other half. Cast bullets carry lubricant in grooves, and its job is to reduce friction between lead and steel as the bullet travels. Different lubricants suit different velocity ranges, and a lubricant that works at mild target velocities can fail at magnum speeds, at which point leading appears regardless of fit.
This explains the mechanisms, not the numbers. Alloy specifications, sizing dimensions and load data belong in a current reloading or casting manual, and should be taken from a manufacturer’s published data for your specific components and firearm. Never exceed published load data, and do not extrapolate from jacketed data to cast or the reverse.
Coated and plated alternatives
Two intermediate options exist between bare cast lead and fully jacketed bullets, and both are popular for good reason.
| Type | Behaviour | Notes |
|---|---|---|
| Bare cast with lube | Cheapest, most fit-sensitive, most leading-prone | The traditional option; rewards getting fit right |
| Polymer-coated cast | Coating separates lead from bore, much less leading, less smoke | Follow the maker's velocity guidance; coatings have limits |
| Copper-plated | Thin copper over a lead core, behaves between cast and jacketed | Usually rated to a velocity ceiling — observe it |
| Fully jacketed | No leading, most forgiving of fit, most expensive | The default when leading is not worth managing |
Polymer-coated cast bullets are the practical answer for a great many revolver shooters. They keep most of the cost advantage of cast, they largely eliminate the leading problem, and they produce noticeably less smoke and airborne residue on an indoor range. They are not unlimited — every coating has a velocity above which it stops doing its job — so follow the manufacturer’s stated range.
Removing leading safely
The wrong methods are the intuitive ones. Steel wool, abrasive pads and aggressive scrubbing remove lead and bore steel together, and the damage is permanent.
- Verify the revolver is unloaded. Every chamber, looked at individually.
- Start with a bronze brush and solvent. Light leading often comes out with patience and repeated passes, and this should always be the first attempt.
- Use a lead-removal cloth on the cylinder face and other exterior surfaces. These work chemically rather than abrasively.
- For stubborn bore leading, use a purpose-made lead removal tool — a mesh or cloth wrap over a jag that grips and pulls lead without cutting steel. These are cheap and effective.
- Consider a dedicated lead solvent, following its instructions exactly, including contact time and neutralisation. Some are aggressive toward finishes and should not be left on the outside of the gun.
- Do not neglect the chambers and throats. Lead and carbon accumulate there too, and a leaded throat makes the next batch worse.
- Protect the crown. Most revolvers are cleaned from the muzzle, so use a one-piece coated rod and a muzzle protector. Crown damage costs accuracy permanently.
Lead removal tools, cloth and bronze brushes
- Mesh or wrap toolGrips lead without cutting steel
- ClothChemical action for cylinder faces
- BrushesBronze for bore, chamber brush for throats
- NeverSteel wool or abrasive pads
Purpose-made lead removal tools use a mesh or fabric wrap that grabs deposited lead and pulls it out without abrading the bore, which is exactly what steel wool cannot do. Pair one with a bronze bore brush, a chamber brush sized for the chambers rather than the bore, and an impregnated cloth for exterior surfaces. All of it costs less than one recrowning job.
Bottom lineCheap insurance against permanently damaging a bore you cannot replace.
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Heavy accumulated leading reduces effective bore diameter and raises pressure. It also degrades accuracy long before it becomes dangerous, which is usually what prompts the cleaning. Do not fire a revolver with visibly heavy bore leading, and if leading recurs rapidly after a thorough cleaning, stop and find the cause rather than cleaning more often.
Ventilation and hygiene
Shooting bare cast lead produces more airborne lead than jacketed ammunition does, and lead exposure is a genuine occupational concern for people who shoot a great deal, particularly indoors.
Sensible practice costs nothing:
- Prefer well-ventilated ranges, and outdoor ranges over indoor where you have the choice.
- Wash hands and face with cold water and soap after shooting and after cleaning. Cold water — hot water opens pores. Wipes formulated for lead removal exist and are convenient at a range.
- Do not eat, drink or smoke while shooting or cleaning.
- Change and wash range clothing separately, particularly if you shoot indoors often.
- Ventilate when cleaning, and treat solvents and lead residue with the same care.
- Take casting seriously. Molten lead produces fumes and casting should be done outdoors or with proper extraction, never in a living space.
- Coated bullets reduce airborne lead meaningfully, which is a practical reason to prefer them for high-volume indoor shooting.
Children and pregnant women warrant particular caution around lead exposure, and anyone shooting very high volumes may reasonably raise the question with their doctor. This is general information rather than medical advice.
Frequently asked questions
Why does my revolver lead so badly?
Most often because the bullet is not sealing the bore, which lets hot gas past it and strips molten lead onto the barrel. That usually traces to fit — an undersized bullet, or cylinder throats smaller than the barrel’s groove diameter, which swage the bullet down before it ever reaches the rifling. Measure before you change components, because buying harder bullets frequently makes it worse.
Are harder cast bullets better?
Not automatically, and assuming so is the most common cast-bullet error. Pressure upsets the base of a lead bullet outward to seal the bore, and a very hard bullet resists that expansion. If the bullet is already slightly undersized, making it harder means it seals less and gas-cuts more. Get fit right first, then match hardness to the velocity you are running.
What are cylinder throats and why do they matter?
The throat is the short section at the front of each chamber that the bullet passes through before leaving the cylinder. If throats are smaller than the barrel’s groove diameter, they squeeze the bullet down and it arrives at the rifling undersized and unable to seal — producing leading no change of bullet will fix. Throats that vary between chambers produce inconsistent accuracy. Both are gunsmith corrections.
How do I remove leading without damaging the barrel?
Start with a bronze brush and solvent and repeated patient passes, which handles most light leading. For stubborn deposits use a purpose-made lead removal tool with a mesh or fabric wrap that grips lead without cutting steel. Use an impregnated lead-removal cloth on exterior surfaces. Never use steel wool or abrasive pads — they remove bore steel along with the lead and the damage is permanent.
Are coated bullets better than bare cast lead?
For most revolver shooters, yes. Polymer coating separates the lead from the bore, which largely eliminates leading, keeps most of the cost advantage over jacketed, and produces noticeably less smoke and airborne lead — which matters on an indoor range. The limit is velocity: every coating has a ceiling above which it stops working, so follow the manufacturer’s stated range.
Is shooting lead ammunition a health risk?
Bare cast lead produces more airborne lead than jacketed ammunition, and it is a genuine concern for high-volume shooters, especially indoors. Prefer well-ventilated or outdoor ranges, wash hands and face with cold water and soap afterwards, do not eat or drink while shooting or cleaning, and wash range clothing separately. Coated bullets meaningfully reduce exposure. This is general information, not medical advice.