22LR Chamber Damage

[redrockranger]

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!

What are the possibility's of it happening again ?

 

[CharlieNC]

What are the possibility's of it happening again ?

I think the damage was caused by the combination of a tight chamber and my manually loading single shot, whereby the neck of the round frequently bumped the paper thin entrance of the extractor groove. The new chamber is not as tight plus I am using mag feed, and so far no more hard bumps when loading rounds. So I'm optimistic this was put to rest.

 

[SGW Gunsmith]

The Menck tool is no longer available as the gentleman who made those has passed. I do have one of those tools near my main bench and it does a good job when rolling the raised metal going into the chamber very well. What it doesn't do, is push the raised metal on each side of the firing pin "ding", back where it belongs. That requires another process so that a .22 cartridge rim will sit flush with the breech face.
I never release the firing pin on an empty chamber in a .22 rimfire. I use these for snap-caps when dry firing:

These are plastic dry-wall anchors, size #4-6 and cost around $5.00 for a box of 100. Each anchor will absorb 10 firing pin hits before the rim is all battered up.
These will even feed manually from a magazine and extract/eject same as a spent case. I don't like to leave a .22 rimfire firearm with the striker or firing pin cocked, so installing one of these wall anchors will allow the firing pin to be relaxed safely and without any chamber mouth damage.