What causes a misfire with .22 LR ammo?

[jrdolall]

I had a misfire yesterday using a sub-sonic ammo out of a Winchester semi. I have shot several boxes of this exact ammo as I use it as my main varmint eradicator around the house. I lined up the shot and got a click rather than a bang. Since this is sub-sonic it normally does not feed well so I basically use the gun like a bolt gun and manually feed each round.

I don't know the internal workings of 22 ammo like I do center fire so I was just wondering how the ammo actually works. There was a clear ding in the bottom of the round and the next time I pulled the trigger the round(different round)went off as expected (bad news for the chipmunk). I did not try to fire the dud again but just tossed it.

 

[Jim Watson]

During manufacture the priming mix is moved to the rim by spinning the brass.
Sometimes there is a little gap. If that is where your firing pin hits, misfire.
Try it again with the round oriented differently in the chamber to be hit somewhere else on the rim. If it doesn't fire then, it either lacks priming compound entirely or maybe it did not get fully dried.

 

[Skylerbone]

^^^^^^^^^^

Further, the priming compound is impact sensitive. Silica is embedded to provide the friction necessary to provide detonation upon impact from the hammer. Jim is of course correct on both instances denoted providing a no-go dud as the prime is stable when wet and does nothing if the firing pin hits a void.

Most every "dud" I've had did indeed fire on being re-chambered.

 

[tommy.duncan]

My Scoutmaster always told us to rotate the round and try a second time. Most of the time the second strike will fire the round.
Jim (post #2) is correct an air gap in the primer.

 

[whughett]

Quite common in bulk pack ammo. That stuff sold on 550 round loose pack boxes. Remington seems the worse but Federal and Winchester both will have a 1/2 dozen or so to a box. Even that seems a little given the production rate.

 

[jrdolall]

Thanks for the info. This was Gemtech subsonic and has been completely reliable for me over the past year or so with maybe 125 rounds fired in sighting in and eradicating pests.
I now have an understanding of how the rimfire ammo ignites which is what I was looking for.

 

[TIMC]

a dirty gun can also cause your problem too. The bullet does not fully seat then will seat the rest of the way when the firing pin hits it but it will leave a good dent looking like it should have fired.

 

[viking499]

Usually, it is caused by coming out of a green box with a big "R" on the side.........

 

[rcmodel]

I know nothing about Gemtech subsonic ammo.

But I have firsthand experience with Aguila sub-sonic causing leading in the chamber from the low pressure failing to bump up the bullet enough to prevent gas blow-by induced leading right in front of the chamber.

As TIMC mentioned above, chamber fouling from lead, bullet grease, and powder fouling can prevent the loaded rounds from fully seating with the rim tight against the breech face so the firing pin has a good whack at it the first time.

Throughly clean the chamber, bolt face, and breech face with a bronze bore brush and powder solvent and see if that helps.

rc

 

[Reloadron]

I had a misfire yesterday using a sub-sonic ammo out of a Winchester semi. I have shot several boxes of this exact ammo as I use it as my main varmint eradicator around the house. I lined up the shot and got a click rather than a bang. Since this is sub-sonic it normally does not feed well so I basically use the gun like a bolt gun and manually feed each round.

I don't know the internal workings of 22 ammo like I do center fire so I was just wondering how the ammo actually works. There was a clear ding in the bottom of the round and the next time I pulled the trigger the round(different round)went off as expected (bad news for the chipmunk). I did not try to fire the dud again but just tossed it.

This is a good video on the manufacture of 22 rim fire ammunition. Once we understand how it is made and works we can understand why it may not work.

Ron

 

[gunnerh]

TIMC is correct, most rimfire misfires are form dirty chambers. In my 50+ years of shooting with 20+ years working government range ammo even the "cheap stuff" is very seldom the cause of a misfire. Weak hammer falls, short stokes of the action and crap build up in the chamber account for the vast majority of misfires.

 

[Skylerbone]

I'm rather religious about cleaning the dozen or so rimfires I own and have, last year alone experienced several dozen misfires from clean chambers with bulk ammo. With up to 4 rifles on the firing line at a time no one rifle gets more than 100 rounds a session unless I'm testing ammo and then it is scrubbed clean between brands. With Eley Primed ammo, never a misfire.

Yes I scrub the chambers using a long pistol brush. I use lead and powder solvents. I tackle heavy fouling with JB Bore Paste. I frequently clean at the range before returning home. I clean every firearm that hasn't seen regular use. Even with the ELE we've experienced with ammo I still shot up some 5,000 rounds last year alone. That may be chicken scratch to some, and I know chamber fouling can prevent solid contact but my experience lately points to poor QC as the likely culprit though we don't know the condition of the OP's rifle.

 

[MedWheeler]

Viking499 writes:

Usually, it is caused by coming out of a green box with a big "R" on the side....

I hear this a lot. Probably gonna get to experience it myself soon. Never bought such ammo before, but just had a Henry lever gun shipped in, and the dealer that received it for me had a box (also had one of those 300-count MiniMag Landry boxes.) I told him as I bought the ammo that I knew the green box should contain "crap" ammo, but figured it should be okay in the Henry and in my Heritage revolver.

So far, however, I've never had a misfire (with rimfire ammo) in nearly thirty years of shooting over tens of thousands of rounds. But, to be honest, better than 75 percent of those rounds were MiniMags, the only stuff available locally back when I started.

 

[RetiredUSNChief]

Lots of people focus on the ammunition itself, and often not without cause.

However, and I believe some people may have addressed this at least in part, the firearm cannot be entirely discounted.

If, for example, you have a weak firing pin spring on a bolt action, occasional misfires might happen. Also, if the firing pin mechanism is gummed up with dirt or years of lubricants which have becomed gummy, or improper lubricants (or lack of lubricants) used), then occasional misfires might happen.

For semi-auto pistols or rifles, if the action is fouled or gummed up then the action might not be be going to "full battery" position...and that slight misalignment may cause misfires. A dirty slide will cause problems. Heck, my AMT Automag II pistol had a problem once where a lost grip screw caused the grip panel on one side to pivot and come into contact with the slide, causing it not to go into full battery...pulled the trigger and all I got was the "snap" sound of the hammer falling but not striking the firing pin.

Then, too, like centerfire guns, some guns just like or dislike certain ammunition and people need to learn what to feed them for proper operation and reliability.


Yes, rimfire ammunition is more susceptable to misfires than centerfire ammunition. And the reasons why have already been discussed. Personally, I don't seem to be having any of the issues that some people have with certain brands (Remington gets bashed a lot). Probably because all my .22 rifles are bolt action and I know the firing pin springs are darned strong in my bolts. My family has gone through several bricks of Remington 22LR in the past 12 months and I can't recall a single misfire in that period. I'm sure I would have remembered, because I don't recall having to do the hands-on teaching for a misfire in that time.)


Bottom line is that if you're experiencing misfires, it may NOT be just the ammunition. Make sure your gun is clean, properly lubricated, and in good working condition as part of the troubleshooting process.

 

[rcmodel]

Another possible cause of missing primer compound in the rim is rough handling.
The compound can become cracked and a piece fall out of the rim.

Bulk pack is probably more susceptible to it then ammo packed in boxes because it takes more abuse in packaging, shipment, and use then boxed ammo.

Also, Ammo dropped on hard floors or concrete is probably more likely to have it happen then ammo that hasn't been dropped.

The way to find out is twist the bullet out of the case with a pair of pliers, dump the powder out, and look down inside the case.

If the primer compound is missing where the FP hit it?

It either was never there?
Or it cracked due to rough handling and a small segment of it fell out into the powder charge before it was ever fired, and misfired.

rc

 

[kBob]

When comparing firing pin strike marks you don't know much by comparing a dud with a fired round.

Most of the mark you see on fired rounds is from the case head being driven back onto the firing pin during firing. If you did pull the bullet (not recommending you do) and fired a case with just priming you would find a much shallower and indistinct firing pin mark than you do on fired actual cartridge cases.

On the other hand light strikes from crud build up in the rifle can certainly cause FTF. I recently had trouble with a Savage Anschutz 164 that had been in storage for ten years. After repeated FTF (and four other rifles in use with the same ammo had zero) I asked on a popular rimfire website and got a tutorial on the 64 series bolt. I cleaned out the tunnel for the firing pin with a pipe cleaner and RBC Hoppe's #9 and got just a little bit of grey color on the pipe cleaner then scrubbed the firing pin with a clean patch and more Hoppe's for even less discoloration. I was sure that was not it. over 100 rounds later and not a single FTF however make me suspect that teeny tiney amount of grundge was slowing things down just barely enough to be a problem.

On autos I have found that crud build up around the outside of the chamber where the cartridge rim sits can provide a cushion the rim sits on and compresses when the firing pin comes forward enough to prevent ignition. As others have said dirty chambers can cause this as well. Remember carbon polishes up right nice and can fool you into thinking you have a clean gun when you don't.

I saw the occassional FTF in quality ammo 50 years ago and I think mainly people that do shoot just shoot more these days so they see more FTFs.

-kBob

 

[Vern Humphrey]

I'm rather religious about cleaning the dozen or so rimfires I own and have, last year alone experienced several dozen misfires from clean chambers with bulk ammo.

Same here -- and I'll second the remarks about Remington ammo. I won't buy it anymore.

 

[clutch]

I've had a bolt action rifle fail to fire because the bolt wasn't fully closed due to the cut out for the bolt handle causing it to be slightly out of battery.

Most of the time with just about anything, my rim-fire firearms go off as they should.

Extremely seldom, I get a round that I have to turn to go off. That is with bulk pack stuff, usually shooting at falling plates out of a pistol.

My higher end ammo for shooting groups and competing in silhouette has never misfired in any firearm I thought worthy of spending 10 cents plus a round to shoot.

Good ammo tends to go off if your firearm doesn't have problems.