Fouled Cylinder Chambers from using .38 in .357

DSCN1676It’s fairly common to shoot .38 Spl from a .357 Magnum revolver for practice or competitive shooting events, as it’s cheaper, and has significantly less recoil, without much difference in accuracy (despite the “jump” it has to make).  This leads to an often brought up topic of fouling making it difficult to load .357 Magnum cartridges after prolonged bouts of shooting .38 Spl.

The problem comes from the fact that the .357 Magnum cartridge is a bit longer (and miniscule bit wider) than a .38 Spl cartridge.


This means the .38 Spl bullet has to jump a bit through the cylinder chamber to get to the forcing cone and into the bore.  This means there will be fouling at a lower point in the cylinder, and that build up and burn in over time (sometimes even after a hundred or so rounds during one session) and make loading of .357 Magnum cartridges difficult to impossible.  See the image below to see a ring of where this buildup was removed from the chambers.


What you end up with is a .357 Magnum Revolver that doesn’t seem to want to accept .357 Magnum cartridges.  Not cool.


Luckily, it’s not permanent.  Even if cleaned normally after shooting .38 Spl, you still may need to go a bit further to remove this fouling.  You could use a slightly oversized brass brush (for instance, a .40 S&W brush in a .357 Cylinder) soaked in solvent and just have at it for a while.  A serious while.  It takes A LOT of effort to remove this fouling this way.  Luckily for you, I’m going to show you the easy (well, easy-ish, more on that at the end) way.

Things you’ll need:


  • Electric Drill (preferably newer than the one pictured)
  • Brass brush of required size (in this case a .40 S&W sized one)
  • Solvent (Hoppe’s 9 / CLP work well, MC25 doesn’t break up the lead as well)
  • Tools for disassembly of your firearm

Naturally this will vary by firearm, but what you’re going to need to do is remove the Cylinder.  My sample here is a Colt Python, so here you’ll get a bonus Colt Python Cylinder Removal quick-guide.

  • Carefully LOOSEN this screw enough to easily turn by hand:
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  • Remove by hand while minding that a very tiny spring and plunger sit inside of it.  It’s not under pressure, but may fall out and be a PITA to find.
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  • Use spur to open the cylinder action, and slide forward off of the frame.
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  • Unscrew the Extractor Rod and remove, along with the parts that are now freed up by this.
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  • Complete.

Yes, that cylinder has some serious burn rings on the front as well.  This Python may have the appearance of a safe queen, but she gets worked out quite a lot thanks to being such a pleasure to shoot.  If there’s interest, I’ll do another quick article on getting THOSE rings off, but the long and short- lead remover cloth, or scotch pads and Hoppe’s 9.

So, what we’re going to do here next is go ahead and chock that brush into your drill.


Soak the brush in the solvent of your choice, and holding your cylinder in one hand and the drill in the other, get that brush in there and let ‘er rip.  This may seem harsh, but the brass stands no chance against the steel inside of your chambers, you’re not going to damage it, but you will break up the fouling like a boss.  For extra-bad fouling, you may want to tilt the drill a touch in circles to apply extra pressure, but not too much or you’ll bend up your brush too much.


When this is done, you’ll have A LOT of dirty solvent all over that cylinder.  Give it a good wipe and normal cleaning.  Once that’s done, move to your test area (because I KNOW you didn’t have ammunition near your work space, right?) and let’s see what happens.


Ta-da!  Your .357 Magnum is back to being a .357 Magnum.

Now, about the EASIEST way of doing this that doesn’t involve jury-rigged powertools.  Just buy this.  Brass screen over a rubber piece will get that fouling out in one pass.  Also works very well at cleaning bores and getting your forcing cone clean.  As a bonus, this is a 9mm size, it works for .38 / .357 / 9mm just like brushes / bore snakes, and one tool for multiple guns is always the way to go.

Cleaning for beginners, Cleaning Kit How-To


Well, I said I would get to this eventually so here goes.  How to get a new shooter up and running with a basic cleaning kit.  I’m not going to go into detail here on the cleaning process, that would best be covered in individual guides- but we’ll do a basic overview of the process and what bits and pieces you’ll want in your kit to let you do so.


So first off, basic break down of the process you should be following as soon as possible after shooting.

  1. ALWAYS Verify firearms are unloaded and remove any ammunition from the workspace.
  2. Field Strip (or as far down as you’re personally comfortable with and feel is necessary at the time, the deeper the better) firearms used one at a time.
  3. Give all parts a brief wipe down with a clean and dry rag (or cloth patch if you like).
  4. Spray parts and surfaces down with MC25 Solvent (my preference, plus it smells nice) and allow to set briefly, or, if you like, simply spray or wipe with a rag/patch soaked with CLP.
  5. Spray chamber and inside of barrel liberally with solvent of choice.
  6. Wipe Solvent / CLP soaked parts with clean rag / patch to remove initial fouling.  Repeat above steps until rag / patches return clean results.
  7. Use CLP soaked (followed by dry) Q-tips (seriously, click link, way better than the ones for your ears) to detail clean Chamber, Breechface,  Lugs, and other detailed areas.  Use pipe cleaners (the absorbent kind, not craft pipe cleaners) to get into harder to reach spots.  Additionally, a toothpick or dental pick wrapped in one layer of thin cloth works pretty well for buildup in tight crevices.  Use solvent-soaked toothbrush for very fouled areas, especially fouling on intricate areas.
  8. Run calibercorrect Boresnake through barrel at least 3 times, ALWAYS from Chamber -> Muzzle.  NEVER pull through from Muzzle end to Chamber.  Wipe down the feed ramp with CLP soaked rag / patch again, just for good measure.
  9. Wipe all parts down with dry rag / patches.  At this point, there should be minimal to no fouling showing on any cleaning material after wipes.
  10. Lubricate per needs of your firearm with oil and/or grease*
  11. Reassemble firearm and wipe off excess oils.  You may elect to SPARINGLY apply a bit of CLP to a rag and rub a protective coating on the exterior metal surfaces of the firearm.  This will depend on storage and intended further use, but can be of benefit when the firearm is going back in a safe for a while.
  12. Cycle the weapon’s action liberally to distribute lubricants.

*Opinions on lubricants is another hot-button issue.  My personal theory here: If you have the money to spend, by all means, Mil-Comm makes great products, and my friends who’ve used their stuff where their life depended on it swear by it.  BUT, on a budget, I figure any jackoff in their basement can slap a cool logo and guarantee on a bottle of mineral oil and come up with a story on how long they spent researching it, then charge an arm and leg for it.  Know who does spend a ton of verified money on high-performance lubricants that need to hold up to a variety of environmental conditions for thousands of hours of intense use?  Automotive lubricant companies, that’s who.  Enter the cheapest-per-volume high-performance firearm lubricant you’ll find, and likely one purchase will keep you lubing for years:


That’s right.  It’s good enough for moving parts in a metal box full of explosions driving a shaft to several thousand revolutions per minute for ~450,000 hours before you should replace it, in nearly any environment you’ll find on Earth.  I think it’ll hold up just fine keeping a couple of surfaces and moving parts slick over the course of a few hundred cycles before it’s wiped off and reapplied.  Similar logic applies to grease- Mil-Comm stuff is the shit, and recommended by SIG for their products.  But Lucas Oil White Lithium Grease is hard to beat with it’s track record and price point.

Additional thoughts-

  • A brass brush, and traditional steel rod with brush attachments are still good to have on hand in case of heavy fouling.
  • A bottle of Windex (or generic ammonia based glass cleaner) is good to have if you’re planning on shooting corrosive surplus ammunition.  Just be sure to clean properly afterwards.  The ammonia doesn’t replace a step in the process, only adds one before you do the first round of solvent.
  • Seriously CLP is awesome.  Have some.  Have extra.  This stuff works for all kinds of stuff, from sticky door locks, to bicycle maintenance.
  • A box of some sort is nice.  I honestly can’t remember from where mine originally came into being.  I believe it was a hard case for one of my father’s old electric grooming devices.  Perfect size for the range bag though, so it just kind of stuck.  Small tool or tackle boxes work pretty well though.
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  • Medical exam gloves are awesome to use while cleaning.  You will get fouling all over your hands.  You will get solvent all over your hands.  You will get lubricant all over your hands.  The pleasant smelling MC25 isn’t too bad to get on yourself, but still best to avoid getting most of these chemicals all over yourself.  Use protection my friends.
  • A Bore Light, such as the one mentioned in a previous post, is a great additional tool to have in the kit, so you can have a look in tight places, and check how spic & span your barrel interior is after running those boresnakes through.
  • As far as a toothbrush, a military-style one that has the large and small bristle area is awesome, but what do I always have around?  Worn out former dental toothbrush, after good cleaning of course.  They last about the same interval anyway.
  • Additionally, a small screwdriver set and punches (as needed by your particular firearms) are good to keep on hand in your kit.

Enjoy, and shoot clean.