Rimfire Rifle Woes/Fixes

[Picher]

The biggest problems with newer rimfire rifles are due to poor quality control, and design.

Failure to fire, often due to one or combination of these:

1. Insufficient mainspring power
2. Poor firing pin nose shape: a. too wide or flat, b. hitting too high on the rim (fold); c. roughness or crud in the firing pin channel.
3. Crud on the bolt or breech face.

Semi-Autos: Failure to eject is most often due to extractors that don't hold the empty case firmly against the bolt recess until it strikes the ejector. It's a simple fix to reduce clearance between bolt face and extractor hook that involves removing the extractor, putting it in a vise and heating the rear lug, then tapping it to reduce clearance. A bit of filing trial/error may be needed to get the right distance between the lug and hook. (This problem is also found on some other actions, but not as often as semi-autos.)

Bolt/lever Actions: Failure to extract is quite common. Re-shaping the extractor hook and/or bolt notch usually cures the problem, but it should be done by a competent gunsmith.

Anybody have any other tips they would like to share about rimfires?

 

[Poodleshooter]

I'd venture that cheap, poorly primed, poorly lubed rimfire ammo is to blame for the majority of .22lr misfires and jams, with extractors and magazines a distant second. Most misfires I see have deeply crushed rims, indicating a lack of priming paste in that section of the rim.
With use of good .22lr ammo (Some Federal and Winchester, and most CCI and foreign made ammo), I seldom have function problems.

 

[Picher]

I agree about ammo, but I was discussing firearm problems that affect accuracy and function.

Poor ignition doesn't have to result in a misfire to affect bullet flight. Most folks won't be able to see the difference, but if a round isn't hit with enough energy, it may shoot off center by more than a quarter inch at 50 yards.

For instance, the first shot flyers people complained about with accurized 10-22s are caused by the operating handle interfering with firing pin velocity by binding it. Loosening the handle fit in the bolt slot cured the problem.

I also found roughness in my Rem 504 firing pin and channel. After honing and polishing, flyers were eliminated.