Cylinder chambers becoming tight.

[emilianoksa]

I have an inexpensive Czechoslovakian 22lr revolver. It's a Kora BRNO, not available in the US.

After 50 or so rounds, in single or double action, some of the eight chambers become very tight, and the bullets have to be forced in.

I didn't know whether this was due to the cylinder getting hot, or to a build up of crud in the chambers. I assumed it was a characteristic of this particular gun. After all, it's no Smith and Wesson.

However, when I rented the range gun, which is a Smith 617, I found the same thing happening.

Is this something one has to expect with a 22 revolver? Is it the result of cylinder heating or crud buildup?

The Kora is an inexpensive gun, but the barrel and cylinder are steel, and Czech arms are generally dependable.

I just wondered if this tightening of the cylinder should give cause for alarm. Might it be dangerous to continue shooting this gun?

I'd appreciate your advice.

 

[gordy]

Clean the gun and see what happens. If it gets better then that solves you problem and if it changes nothing then there is something to think about.

 

[emilianoksa]

I clean it religiously after every session (never more than a hundred rounds), and when clean, there is no problem at the start of the next shooting session.
The tightening is a gradual process.

I know 22 is a dirty little round, and I'm coming to the conclusion that the crud builds up very quickly.

I would be surprised if 22 rounds could heat up a cylinder to such an extent that the chambers would contract. However if I fire off all eight rounds quickly in double action, it does seem to get quite warm.

Is the chamber of a revolver more prone to this kind of thing than the chamber of a semiauto? I have no problems with my CZ 75 Kadett.

Thanks for your reply, by the way.

 

[gordy]

Try a different kind of ammo if you can. It may be that.

 

[average_shooter]

In my experience what you describe is normal for revolvers. Letting the cylinder cool down may help a little bit, but in the end the carbon build-up will cause the chambers to be tight. Just clean it and keep shooting. You might even just take a wire brush and a little solvent with you to the range and take care of it right on the line so you can keep shooting.

I've noticed the same happening with S&W's, Ruger GP-100's, SAA Uberti's, etc. I usually just wipe the crud out of the chambers and keep going.

 

[emilianoksa]

Thanks for the suggestion.

I've only used Winchester Super X copper washed round nose so far.

 

[cerberus65]

Did you put the same ammo through the 617 that you used in the Kora? If so, maybe you've got especially dirty ammo. Might be worth trying a different brand.

Chambering a round in a semi-auto is a whole different deal. You've got the slide coming forward under the influence of a spring to shove rounds into the chamber.

 

[emilianoksa]

Thanks for the explanation.

Yes, I always use good quality American ammo. The best I can get here is Super X, so that's what I get.

 

[The Bushmaster]

I've had nothing but problems with Winchester .22 ammunition. You sure there isn't another quality brand that you can get? Like CCI Mini-Mags?

 

[Maj Dad]

I used to get that in my Ruger Single Six. I just brought a short cleaning rod & brush if I planned on lots of shooting off a bench. I don't recall any ammo being better - they all seemed to dirty up the chambers.

 

[David E]

Heat makes metal expand, not contract.

Change ammo brands. Try several makes and see which one works best.

Carry a chamber brush.

 

[GP100man]

Maj Dad hit on it , take a brush & during your problem scrub out the chambers & see if it helps !

I`m thinkin lube build up , that`s what I run into !

 

[rcmodel]

I shot my new old S&W Model 34 22/32 Kit gun (Made in 1958) for the first time day before yesterday. It was unfired until then.

Using Winchester Super-X, all rounds drop in the chambers.

Using Remington Hi-Speed some rounds drop in freely, and some have to be pressed all the way in the chambers. That conclusively leads me to believe all the bullets are not the same diameter.

Using Winchester Pistol Match, and CCI Standard Velocity Target, all have to be pushed in and seated the last 1/8".

The tighter bullet fit in the chamber throats should promote better accuracy, so it is not a bad thing.

rc

 

[MachIVshooter]

Heat makes metal expand, not contract.

Correct. But it doesn't only expand in one direction. Expansion of metal will reduce the ID of a hole within; The chamber(s) may become tighter in addition to increased OD.

That said, I'm in agreement with others that it is an ammo issue. It's really hard to get a .22 hot enough for this to be a temperature related problem.

 

[gdesloge]

"I didn't know whether this was due to the cylinder getting hot"

A friend of mine who is an excellent mechanic told me that the only fact of value that he has retained from his time in the navy is that a hole in metal, when heated, will expand. That is why heat is sometimes used to loosen bolts and studs - the hole containing them will expand slightly.

gd

 

[MCMXI]

Correct. But it doesn't only expand in one direction.[strike] Expansion of metal will reduce the ID of a hole within;[/strike]

David E is correct. If you heat a metal ring, the O.D. will increase and the I.D. will also increase. I can make a post with the theory if you like. This isn't intuitive but then again, not much in engineering is. I take a flask of liquid nitrogen down to our machine shop from time to time when they're trying to press a bearing over a shaft. We cool the shaft and heat the bearing (in an oven) and assembly goes from impossible to easy in just a few minutes!!