Why Does .22LR Misfire?

.22Plinkster talks about the 4 scenarios that could cause a misfire in a rimfire gun.

This first three reasons are pretty straightforward. A bad firing pin due to dry firing, Ammunition quality, and ammo longevity. The fourth reason is rather interesting and may be enlightening for you as it was for me.

Nicholas C

Co-Founder of KRISSTALK forums, an owner’s support group and all things KRISS Vector related. Nick found his passion through competitive shooting while living in NY. He participates in USPSA and 3Gun. He loves all things that shoots and flashlights. Really really bright flashlights.

Any questions please email him at nicholas.c@staff.thefirearmblog.com


  • Incredulous

    I have taken apart in the dozens of misfired 22 rounds to determine if it was the firearm or the ammunition. I shoot new manufacture 22 ammo, not old ammunition (which may have “aging” issues that are different) and have never seen the priming compound do the shifting off of the brass as he describes.

    What I have seen is incomplete coverage of priming compound in the rim. The misfire is caused by hitting an area of the rim that doesn’t have compound. Rotating the cartridge 180 degrees will get you back to where there is compound. From looking at misfired cases they seem to fall into 2 categories, first there appears to be insufficient compound and inconsistent application where it doesn’t appear to make it fully around the rim.

    The second is where there appears to be sufficient compound but it has “pooled” to one side. The priming compound during manufacture is applied as a liquid/paste and and put into the rim area possibly by spinning the brass. It is allowed to dry with the case standing upright, the thickness of the priming material is enough to keep it in the rim if left standing. The misfired cases of this second category appear to have had the case fall on it’s side before the compound has dried, allowing the priming compound to run out of the rim at the top half, this is easy to see as there is dried compound internally along the side of the rim.

    • M.M.D.C.

      I was a little skeptical about that last bit myself. If you look at this video of the CCI 22 production line you see the primed cases and the finished rounds being tossed about a fair bit. https://www.youtube.com/watch?v=t5qMsmucXhI

      Quality control is probably to blame for most misfires, otherwise certain brands wouldn’t have bad reputations.

  • gunslinger

    essentially it is 2 categories
    1) the firearm is at fault, i.e. the firing pin doesn’t make contact with the primer
    2) the ammo is at fault, the primer doesn’t ignite.

    i tink #1 is pretty straight forward. if the gun is at fault, you probably aren’t getting many shots off.

    #2 is where it branches out. degraded components, improper levels of components, improper manufacturer.. etc.

  • cottonjeff

    There are no .22LR snap caps that I know of. I can only find dummy rounds. And by the way, I agree with you on life span. I am shooting ammo here lately that was bought around 1962 and it is very reliable. I never dry fire rim fires either. You are correct about that.

    • Nicholas Chen

      Yeah I have found plastic dummy rounds designed for dry firing.

      • HSR47

        I’ve also heard of people using plastic screw anchors of the appropriate size as snap caps.

  • Martin M

    The .44 Henry Rimfire was sufficiently unreliable due to unequal distribution of primer that Henry Rifles had a dual firing pin.

  • patrickiv

    I’m having a hard time believing that last bit.

  • Phillip Cooper

    Good, informative article. I’d like to know the most dependable brands, as I want to shoot an Appleseed match soon and will be using my .22 subcaliber kit with my AR.