Is carbon ring theory a myth? Let’s try prove / disprove

There is no "pressure spike" caused by carbon rings. The only minor problem is extraction with the longer cases. Keep your chambers clean and it will never be a problem.

After 30 or 40 cast lead 44 Specials, I tried to feed some cast lead 44 magnums in the Blackhawk and they wouldn’t load. Copper brush with no solvent through each cylinder fixed the issue right away.

Cast lead can put that ring in the cylinder pretty quickly.

And don’t forget most cast lead handloaders are shooting fatter bullets so the loading issue surfaced earlier—in this case .432s which were meant for the lever rifle. Per SAAMI, 44 magnum rifles are .431 while revolvers are .429.

I have zero problems shooting the .432s through the Blackhawk, so long no diet of Specials precedes the magnums.

In manufacturing, light reflection / refraction and vision is used to detect surface imperfections so small they cannot be measured by micrometers or calipers.

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Well - after reading about that sort of thing all I can say is - your statement is at best, misleading.
It's nowhere near just holding up something and giving it the old eyeball.
https://www.tandfonline.com/doi/pdf/10.1080/15599612.2016.1166304

I'll stick with the micrometer &/or digital caliper.

Anyhow - it's all moot. I prefer in this case to err on the side of caution.
Life experience has taught me that you don't diddle around with - weights over 300 pounds & pressures over 90 psi & steam at any temperature - w/out considering all the things that could go wrong, no matter how unproven they may be.

So - until such time as someone buys the equipment to measure the actual pressures - buys the necessary ammunition - takes the time to - prove it one way or another......I'm going to do as I've always done.

I shove a spent magnum case (or Stinger in the case of a .22) into the chamber to scrape out the crud - run a brush in to clear out any debris - then go with magnums.
OR - since I'm a reloader, I just load everything I shoot in the longest case and reduce power levels as needed.

Speedo66 said:

Where did you hear of this "carbon ring pressure myth", I've been shooting over 60 years and I've never heard of it.

Shoot enough .38's in a .357 and a ring will form, period. Never heard of a pressure myth attached to that.

Is this some theory postulated by interweb "experts"?

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The first I heard of this "pressure spike" was relating to Fredom Arms revolvers.

My great uncle told me that they practiced with 38s in their M-19s in the Police Dept. and some carried the 357s and others did not. But generally, 95% of the rounds fired through these were .38s.
Some struggled to get 357 Ammo into the cylinders because of the ring. They often would cram them in there anyways, and fire them away.
They would fire the last 6-12 rounds of 357 sometimes. Regular cleaning solves the issue, not sure if any pressure issues exist, but i could see 357 fired cases getting stuck in tbe chambers because of the carbon 38 ring. This can be mistooken for a pressure spike, a sticky 357 case extraction?

Can't believe three pages on this. Crap builds up ahead of the case. Clean it.
I'd like someone to play with a 460. Shoot a hundred 45 Colts. Try a 454 for fit. Shoot whatever number of 454s you can stand. Try 460.
Or go easy way with a 327 Fed. 32 s&w, 32 long, 32 h&r.
Compound it with lead cast and lubed slugs.
All common wisdom which ain't too common in gubmint circles.
No offense meant.

Not a carbon ring:

I bought a used but in nice shape, Taurus Raging Bull in 45 Colt. (Yes, Virginia, 45 Colt, not 454 Casull.) At the range 45 Colt factory loads would not fully chamber. Upon examination, I found a ring of lead where the chamber narrows into the leade. Easily removed with a toothpick, it came out still as a ring. I have no idea what somebody was shooting in it, but it’s a safe bet it wasn’t jacketed.

PapaG said:

Can't believe three pages on this. Crap builds up ahead of the case. Clean it.
I'd like someone to play with a 460. Shoot a hundred 45 Colts. Try a 454 for fit. Shoot whatever number of 454s you can stand. Try 460.
Or go easy way with a 327 Fed. 32 s&w, 32 long, 32 h&r.
Compound it with lead cast and lubed slugs.
All common wisdom which ain't too common in gubmint circles.
No offense meant.

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Not gonna be an issue with a .460. Only the .45Colt in a minimum spec .454 chamber.

Ru4real said:

I agree. I think the comments about probably a small percentage of law enforcement are the most interesting. I’m not a cop, and I won’t judge. But dang, can’t chamber 357?

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Again, this issue has nothing to do with shooting .38's in a .357.

I've put as few as 100 rounds of dirty 38's through a 357 and then fired 50 factory 357's The 357's wouldn't drop in and I gave them a little push. They fired fine and I still have my fingers. Why you wouldn't clean between sessions is beyond me.

As Craig points out the problem is if the carbon ring is thick enough that the case mouth can't open. So shooting 45 Colt and then following 460 magnums wouldn't cause this issue. Maybe if you shot a stupid amount of 45 colt first, but I don't shoot anything from my 460's anymore accept 460 ammo, or 454 at a minimum. But Neither round is fun enough for long sessions, so it's never a problem.

Simple answer is clean the gun, or shoot the magnums first and then clean.

Now carbon rings aside. I bought my Ruger SP-101 brand new and .357's would stick and be very hard to extract no matter how clean. Ended up figuring out that it had some heavy machine marks inside the cylinder. I found 400 and 800 grit ball hones and honed out the cylinder and now it extracts smoothly. The funny thing is it never gave me any trouble with .38 special. I guess the brass was forming into the machine marks.

CraigC said:

Not gonna be an issue with a .460. Only the .45Colt in a minimum spec .454 chamber.

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why no problem with .460? Looser tolerances in S&W’s?

Yep, the .460 is way too long for it to matter.

So just to get this straight.
A. The carbon/lead/lube ring is a real issue.
B. For most anything other than the FA 454s it is generally inconsequential aside from sticky extraction. (From my experiences).
C. Clean your damn gun and stop worrying about it.

Does this pretty much sum it up?

Hold yer horses, everyone. There were two questions in the original post:

Ru4real said:

How many rounds have you fired, what gun, caliber, such that the longer cartridge would no longer just drop in?

Have you seen fired cases that have a bottle neck shape due to the carbon ring?

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So shouldn't we focus on these instead of duking it out?

Personally, I've never take it so far that they wouldn't just drop in.

I've also never seen a case shape change.

I wipe down the outside of any revolver I shoot every time, in order to prevent rust. I clean the bore and cylinder every few hundred rounds, which could be years for me.

Ru4real said:

Pretty much sums it up, but to add a couple details, in CAPS to your post

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But the reason I was very short with my points is because every time someone tries to qualify their statements for or against the points we begin the same back and forth arguments.
I was trying to boil it down to the FACTS as far as any one of us can prove outside of a laboratory environment, which none of us have in our basement.

Just like "how many licks does it take to get to the center of a Tootsie Pop" ?
The world may never know.