22LR Chamber Damage

[CharlieNC]

I have a CZ457MTR in 22lr with approx 500 rounds through it. While chambering a round has always been tight suddenly I could not chamber one, so I checked it out with the bore scope. Between the chamber and the extractor grooves, the wall is VERY thin and at the entrance the extractors apparently forced a small dimple into the chamber. These dimples snag the bullet as evidenced by clear marks on the bullet. Also the notch to chamber junction wall has a small chip at the entrance. Due to the tight fit I think lead bullet scrapings got into the notch, which forced the extractors to push into the chamber wall resulting in the damage.

First, does this sound reasonable. Second, can this simply be repaired by chasing with a reamer. Third, is such a thin wall between the extractor notch and the chamber normal?

 

[6ShotsOr5?]

Can you post the picture?

 

[Stumpy1]

Without seeing the damage, it is hard to know for sure, but could a chamber iron work to push the divot back out? Fairly common with firing pin dents, and might work for this.

Menck Chamber Ironing Tool 22 Rimfire

Swages out burrs in .22 chambers caused by excessive dry firing. Simply insert and turn, or tap against burr until chamber is smooth and round again....

www.midwayusa.com

ChamberMade Chamber Ironing Swage

Shop for ChamberMade Chamber Ironing Swage - a must-have in gunsmithing tools. Get precise results every time with this reliable tool. Made for .22lr, .22long, .22short

www.tandemkross.com

Hope this is useful to you,

Frank

 

[mudduck]

I’d send it back to cz. Their customer service is excellent or was any way.

 

[CharlieNC]

Without seeing the damage, it is hard to know for sure, but could a chamber iron work to push the divot back out? Fairly common with firing pin dents, and might work for this.

Menck Chamber Ironing Tool 22 Rimfire

Swages out burrs in .22 chambers caused by excessive dry firing. Simply insert and turn, or tap against burr until chamber is smooth and round again....

www.midwayusa.com

ChamberMade Chamber Ironing Swage

Shop for ChamberMade Chamber Ironing Swage - a must-have in gunsmithing tools. Get precise results every time with this reliable tool. Made for .22lr, .22long, .22short

www.tandemkross.com

Hope this is useful to you,

Frank

Those tools look perfect, I did not know about them. Thanks for the info.

 

[Ggmac]

First give it a good cleaning , especially the end of chamber beginning of rifling . Have you dry fired it alot ?
the Menck chamber iron tool works great . Good luck

 

[CharlieNC]

First give it a good cleaning , especially the end of chamber beginning of rifling . Have you dry fired it alot ?
the Menck chamber iron tool works great . Good luck

Cleaning was the first step but not an issue, cannot even get the bullet into the mouth of the chamber. The scrapes on the lead bullet at 3 and 9 o'clock where the extractor grooves are located reflect the problem. I'm surprised how thin the extractor groove chamber wall is.

 

[Woodspook]

I am with mudduck, send it back to CZ for repair. The extractor cuts are too deep. Ironing the walls is only a temporary fix.

Royal

 

[PigButtons]

Even companies as good as CZ have flaws that get out the door. Honest mistake that I'm sure they will make good on.

 

[CharlieNC]

Received a RA and prepaid Fed Ex from CZ so it will be going back. So far so good.

 

[skeetlee]

i understand what your speaking of as i have seen this in my shop more than once. i dont usually try and fix these issues as its just gonna happen again and again. i machine the breech end a bit different than cz does and its the only way to correct these issues.

 

[CharlieNC]

i understand what your speaking of as i have seen this in my shop more than once. i dont usually try and fix these issues as its just gonna happen again and again. i machine the breech end a bit different than cz does and its the only way to correct these issues.

Thank you for the reply. The thin wall seemed like an invitation for damage to me, but I know little about the 22. If this happens again I will contact you about a replacement.

 

[SGW Gunsmith]

Unfortunately, the Menck chamber ironing tool is no longer available, unless you maybe could find one on ebay. I have one, and it does indeed roll the chamber mouth ding out of the chamber mouth, but that's all it does:

It does not put the rolled over metal back into place at the sides of the ding. Another process is required to attempt that issue.

 

[CharlieNC]

Unfortunately, the Menck chamber ironing tool is no longer available, unless you maybe could find one on ebay. I have one, and it does indeed roll the chamber mouth ding out of the chamber mouth, but that's all it does:

It does not put the rolled over metal back into place at the sides of the ding. Another process is required to attempt that issue.

I sent it back to CZ, it will be interesting to see how they correct it. I'll be able to see if it's a new barrel or a repair.

 

[spclark]

This same phenomenon troubled a semi-auto ‘sporter’ rifle put out by Thompson Center years ago.

Extractor could ‘peen’ over the Very Thin Chamber metal right at the breech-face, resulting in what you describe.

They had a recall but despite having one of these rifles (that hasn’t yet shown evidence of this happening) I don’t remember what they were offering to remedy the defect.

 

[CharlieNC]

Good news, CZ is finished. They stated the inability to chamber a round could not be determined because it appeared the chamber had been modified by something like a deburring tool, but replaced the barrel as a courtesy. Interesting since the chamber has not been touched since it left the factory. Good service, I will be more gentle in the future.

 

[DGP4]

They are saying YOU damaged the barrel which seems to me very unprofessional unless they could point to evidence of it. They seem very snarky to me!

 

[nicholst55]

There is a tool available for making this repair, that replaces the out-of-production Menck tool:

Tips On How To Easily Repair Rimfire Dry Firing Damage - Guns in the News

Above: Dry firing a .22 can peen the breech face so that a cartridge has difficulty—or is impossible—to chamber or extract. We all know that dry firing a rimfire cartridge firearm can damage the chamber edge to the point of rendering the firearm inoperable. With an inexpensive tool and the ...

gunsinthenews.com

 

[CharlieNC]

Received from CZ with the replacement barrel, which is free of internal machining gouges too! Finally had a chance to shoot yesterday. First of all the rounds chamber easily, unlike with the original. Three ammo brands shoot a ragged hole 5-shot group at 50yd when I can "manage" the recoil properly using the Harris bipod. I forgot how frustrating and humbling that aspect can be with a 22, but training with it led to my best Ftr scores last year. Quit whining and back on the belly!

 

[Rook 6]

Without seeing the damage, it is hard to know for sure, but could a chamber iron work to push the divot back out? Fairly common with firing pin dents, and might work for this.

Menck Chamber Ironing Tool 22 Rimfire

Swages out burrs in .22 chambers caused by excessive dry firing. Simply insert and turn, or tap against burr until chamber is smooth and round again....

www.midwayusa.com

ChamberMade Chamber Ironing Swage

Shop for ChamberMade Chamber Ironing Swage - a must-have in gunsmithing tools. Get precise results every time with this reliable tool. Made for .22lr, .22long, .22short

www.tandemkross.com

Hope this is useful to you,

Frank

Works very well