To clean a .357 revolver after shooting .38 Special, unload it completely, clean each cylinder chamber as well as the barrel, remove loosened residue, and finish with the lubrication and checks specified in the owner's manual. Pay particular attention to deposits inside the chambers. A clean bore does not tell you whether those separate surfaces are clean.

This guide covers routine cleaning of swing-out-cylinder revolvers approved by their manufacturers for both cartridges. Single-action revolvers have different unloading and cylinder-access procedures. Always use the manual for your exact model.

Why .38 Special leaves a ring in .357 chambers

The .38 Special case is shorter than the .357 Magnum case. Firing the shorter cartridge can leave a fouling ring ahead of its case mouth inside the longer chamber. That deposit may contain powder residue, lead and bullet lubricant, rather than carbon alone. SliXprings explains this mechanism in its chamber-fouling guidance.

This internal ring is different from the dark marks around the openings on the cylinder's front face. Cleaning the visible face does not clean the chamber walls. Heavy chamber deposits can interfere with cartridge seating or extraction, so do not dismiss them as a cosmetic issue.

Unload and prepare the cleaning area

Keep the muzzle in a safe direction and your finger outside the trigger guard. Open the cylinder as the manual directs, remove every cartridge and case, and inspect every chamber individually. Keep ammunition away from the bench throughout cleaning. The NSSF firearm safety rules emphasize checking for yourself rather than assuming a firearm is unloaded.

Let the revolver cool. Wear eye protection, ventilate the area and follow the cleaning-product labels. Wash your hands afterward. Leave the cylinder open and do not remove sideplates or internal parts for this routine.

Choose tools for the bore and the chambers

The .357cal/.38cal/.380cal/9mm Gun Cleaning Bore-tips® by Swab-its® provide a caliber-matched foam option. The six-piece bag, SKU 41-0901, contains washable, reusable, lint-free tips with an 8-32 thread for a compatible cleaning rod. Use them to apply solvent, lift loosened residue and dry cleaned surfaces.

The .357/9mm Bore-tips six-piece pack provides separate tips for solvent application, residue removal and drying.

Also gather a non-abrasive cloth, a soft utility brush, approved solvent and lubricant, and a brush specifically suitable for your revolver's chambers. Bore size and chamber-cleaning requirements are different considerations. Ask the firearm or cleaning-tool manufacturer about fit rather than forcing a larger brush into place.

Foam swabs are useful alongside the appropriate brush. They are not a substitute for every method needed to remove a stubborn ring.

1. Clean each cylinder chamber separately

Support the revolver securely without putting sideways pressure on its open cylinder. Apply a small amount of approved solvent with a correctly fitted swab. Let it work only for the dwell time on the label. Do not mix cleaners or assume that a longer soak is better.

Use the approved chamber brush as its instructions and the revolver manual direct. Keep the tool aligned and work through each chamber in turn. The Ruger GP100 manual specifically calls for removing bullet-metal and firing-residue buildup from the chambers, which can otherwise prevent cartridges from seating fully.

Follow with a Bore-tip where it fits without force to collect loosened material, then a clean, dry tip. Blot dirty foam onto a cloth between passes. Inspect each chamber under good light instead of judging the entire cylinder by the first chamber cleaned.

Clean every chamber individually, with the revolver unloaded and the cleaning tool aligned with the chamber.

If deposits remain after the approved routine, stop and consult the manufacturer or a qualified gunsmith. Do not use a drill, improvised scraper or polishing compound to turn a cleaning job into metal removal. Never force a cartridge into a tight chamber or fire ammunition in an attempt to clear fouling.

2. Clean the barrel with the correct access method

Follow the revolver manual's barrel-cleaning procedure. A swing-out cylinder does not necessarily provide a straight rod path through the barrel from the rear; the GP100 manual, for example, specifies muzzle-end access. Protect the crown and avoid levering the rod against it.

Apply approved solvent with a caliber-matched Bore-tip, brush when required, and remove the loosened fouling. Finish with a clean, dry tip. Insert foam tips straight rather than bending their necks. Our Bore-tips use and cleaning instructions also explain blotting, washing and completely drying the tips before reuse.

3. Wipe the extractor area and accessible surfaces

On models with an extractor star, follow the manual to clean its underside and seating surface. Trapped debris here can interfere with seating and cylinder movement even after the chambers have been cleaned. Wipe away loosened dirt rather than pushing it into openings, and do not flood the mechanism.

The 9-Piece Gun Cleaning Foam Swab Kit of Gun-tips™ by Swab-its®, SKU 81-1209, includes four swab sizes for accessible detail work. Choose a head that reaches the surface without forcing it into a narrow gap. The foam is lint-free, washable and reusable.

The nine-piece Gun-tips kit offers several head sizes for accessible surfaces around the cylinder and frame.

4. Respect the cylinder material and finish

Do not chase every dark mark with an abrasive. Titanium cylinders, plated surfaces and other finishes can require special care. The Smith & Wesson revolver manual expressly warns against abrasive cleaning of its titanium-cylinder chambers and front face because it can damage their protective surface.

That warning is a reason to check your own model, not to apply one brand's procedure to every revolver. A cleaner that is compatible with a foam swab may still be unsuitable for the firearm's finish. For other avoidable problems, review our common firearm cleaning mistakes.

5. Inspect and lubricate before putting the revolver away

Check that all swabs and other cleaning materials have been removed. Lubricate only the locations and amounts specified by the manufacturer. Remove excess liquid, and perform only the prescribed unloaded checks. Do not bring live ammunition to the cleaning bench to test chamber fit.

Before loading or firing later, remove any storage lubricant from the bore and chambers as directed and confirm that the barrel is unobstructed. Persistent stiffness, difficult extraction or suspected damage needs qualified inspection; do not assume that more cleaning will fix it. Store the unloaded revolver securely against unauthorized access.

Inspect the chambers after .38 Special sessions and follow the maker's cleaning interval. Before changing to .357 Magnum, make sure chamber fouling has been addressed. There is no universal round count for every ammunition and revolver combination.

Keep chamber cleaning part of the routine, alongside barrel care. Browse our handgun cleaning products for caliber-matched Bore-tips and detail-cleaning Gun-tips to keep on the bench.