Thread: Misfires

I had a couple yesterday so thought I'd outline the causes and prevention.

The two dangers are that:
It may be a hang fire (delayed detonation) and explode after it has been ejected.
A projectile may be pushed partway down the barrel resulting in burst barrel of another shot is fired.

Not closing the bolt fully
Releasing the trigger allows the firing pin to fall but with reduced force. Said to be the most common cause. The round fires just fine when tried again.

No powder in reloaded case.
Very dangerous. Can result in stuck bullet and "overpresure failure" . Darwinian.

Dud primer in reloaded cartridge.
Due to oil or water contamination. Apparently this is an uncommon cause.

Blocked / broken firing pin or spring problem.
How common is this ?

Headspace. Case much shorter than chamber so it moves when hit by firing pin.
How often does this actually result in a misfire and how often does it just give variable ignition ?

Originally Posted by Bagheera

Headspace. Case much shorter than chamber so it moves when hit by firing pin.
How often does this actually result in a misfire and how often does it just give variable ignition ?

I have come across this a few times now each time it has been CCI 250 primers,

Once I figured out the issue & replaced the primer with a Fed 215 the problem disappeared.

I'm yet to have a failure to fire with a Fed primer

I have had a few rounds fail to go, but that wasn't the primers fault, it was the lack off powder in the case leaving the base of the bullet sooty

Failing to seat the primer fully is another common cause

I had the problem with Barnaul ammo in my 308. Changed ammo brands and never had an issue.

Ammunition that has gone through the washing machine due to poor pocket policing has gotton me more than once.

Originally Posted by Marty Henry

Ammunition that has gone through the washing machine due to poor pocket policing has gotton me more than once.

Just don't forget to take ya rifle out of ya pocket otherwise this could be another cause

Originally Posted by Driverman

Failing to seat the primer fully is another common cause

Had a couple of these, one bit that’s good with a blaser is it won’t let the bolt close

The only misfire I have ever had was last year with a Remington factory round.
It was in a lever action so not a bolt closure problem. Repeated cocking and firing still got no response, so the offending round is sitting in the bottom of a swamp in the Kaimais.

had it quite a bit with my .223 when I first got it,then knowledgeable mate showed me how to release spring tension when bolt out of rifle (has added bonus it wont go back in should someone try) and have never had an issue since.
old .410 wouldnt fire cartridge if primer seated below flush as a lot are.
bro in laws single bakail would misfire if it wasnt slammed shut as the opening/cocking lever wouldnt go right down ...that was cheap fix for gunsmith but took a bit to figure out what was going on....I believe Greg Duley had similar issue with a Begera he was test firing????
remington hypersonics had me misfire with shotgun...not so much a misfire but short stroking action as they booted the shite out of me...faarkin horrible rounds....

I had about a 10% failure on my 6.5x55many years ago. I finally found a recipe that worked then a dud batch of primers really fucked up a weekend hunting wallabies. Always take a spare rifle now. I always suspected it was the Murom primers but never tried again. Now I am reloading for 303 and I find out that Winchester primers have been doing the same. Looking at CCI now.....or stick with factory.

Only missfires ive had have been due to dud primers
I had a batch of winchesters a few years ago that one in every 10 didn’t go off
The final straw was a primer bloweing out the side and damaging the bolt face
Apparently this is Caused by Corrosion in the brass primer cups
Since switched to cci and no issues at all since

Shooting mate had a couple 2 weeks back in his 7m08. First time for him and with a good recognized brand of ammo.
Checked the bolt the next day after a second one. Plenty of firing pin pocking out, striped bolt and check all OK. Cartridge had only a light dent in the primer.
Can only assume that he has a max length chamber and a batch of min length cartridges.
Rifle is a main stream american brand but is a budget model.
Z

Hi, thanks it looks as if a lot of people are blaming the primer.

Here's a page which says failure to fully close the bolt is a common problem:
Understanding Misfires - Guns & Ammo

In my case, this was a 2 lug bolt and I've used a 3 lug for several years and my .22 has even less turn than that, so its possible I stuffed up ...

In older rifles the firing pin spring may have lost quite a bit of its zing. It may not cause mis-fires, but but it can bugger up accuracy due to inconsistent ignition.

Its not uncommon in 22's with people thinking "my old 22 has lost its acuracy, maybe I better clean it". A bit less common in centre-fires but I had to change the spring in a Mauser Kurz I rebuilt, there were no mis-fires but the firing pin was being pushed back into the bolt, leaving very odd looking primers, and accuracy was horrible. Made and installed a new spring and both issues were resolved.

I got it a lot on my 17HMR using CCI.
Swapped to Federal and Hornady and it stopped straight away.

With the CCI stuff I could eject the round, see a good firing pin strike then put it back in the magazine turning the shell 180 degrees, re chamber and it would often work fine. Frustrating for sure.