Short COL can cause misfire?

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gifbohane

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I had 3 failure to fires with my 9MM today. All three had no primer strike and the COL was 1.200.

The primer did not show that it was struck by the firing pin. The primer was just flush with the bottom of the case. Could the shortness cause the firing pin to miss the primer? I cannot think of anything else.

Any thoughts?
 
Since the 9mm headspaces on the case mouth, was the case pushed into the chamber by the slide slamming home because the case mouth was taper crimped a bit more than usual?

Just a thought..

Stay safe.
 
Your length of 1.200 is actually over the SAAMI max OAL spec of 1.169. Did you mean 1.02?

"Short" OAL is actually subjective; it's based on the profile of the boolit you're loading.

If the gun went "click" and the firing pin did, in fact, fire then IMO the most likely reason for it to not reach the primer is failing to headspace correctly.

9mm headspaces on the mouth of the cartridge, and if your neck diameter is too small (SAAMI spec for this is .380, considering a .3555 diameter bullet), then it's possible for your cartridge to have gone too far forward, preventing the firing pin from reaching the primer.

Check your neck diameter.
 
Straight walled pistol cases like 9mm and 45acp tend to get shorter the more times they are fired. As they grow shorter they are still held against the breech face by the extractor. I wouldn't suspect your COAL to be the problem.
 
OAL by its self cannot, too much taper crimp letting the case mouth get past the end of the chamber can. A really short cases could.

But most likely, it's a primer not seated fully.
 
maybe the bullet was jammed into the lands as it was too long and the gun wasn't in full battery similar to what happened to my new cz 97b. not in full battery but close enough that the hammer fell but no primer strike on the bullet. i had posted a thread on it with a video of it happening(i didn't realize at the time that the gun wasn't in full battery but you could notice it on the video that the slide was just slightly short of full battery- it was the good folks on this forum that clued me in as to what was happening). if you're interested just search cz 97b. it's on the previous page from this current one. the bullet was hard to eject also. the gun behaved better with shorter bullets but i'm still deciding how long is still reliable.
 
We need more detailed information.

What gun are you using?

What bullet are you loading?

Is 1.200" the actual overall length, or is that a typo? A noted, the maximum SAAMI overall length for the 9mm Luger is 1.169". Your load at 1.200" is way long.
 
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Did you make a second attempt to fire them? If it is a primer seating problem, a second strike will usually set them off. Can you post a pic of the case bases showing primers and headstamps? You didn't happen to get some .380 brass mixed in with 9mm, did you? I've heard of that happening.... but I don't remember who told me. ;)
 
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Sorry guys I meant 1.120 or some were 1.119. I put them back in a magazine and they fired the second time around.

Thanks you for all the help... and yes I might have crimped them too much I have to look at that. They all plunked in a Wilson case gauge before I tried to fire them and afterwards I measured the FTF rounds at home and they also case gauged.

Also I am firing a CZ 75 B (new) and using Hornady 115 grain round nose bullets with 4.3 grains of HP 38. Brass was once fired Win.
 
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Blue 68 - You could be on to something. It was very cold and maybe the grip had something to do with it. What error would have been involved?
 
Would it be possible for you to try some factory ammo to also test this problem? And if you do so would please share the COAL of the factory ammo that did or did not work?
 
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I just started reloading for my CZ 75B and found my OAL needed to be 1.100. I used Hi Tek coated TC bullets.
 
Firing Pin Safety, causing misfires?
The firing pin safety keeps the firing pin blocked until the trigger is pulled. This
safety device minimizes the risk of accidental discharge through mishandling such
as when a loaded pistol is dropped.
 
Set the ones that did not fire in a line with some that are 9MM on the headstamp. I have seen 380 brass sneak through and they drop into the chamber so far the FP will not hit them. If not then I am thinking the grip safety also.
 
If they all went bang when you hit the loud button a 2nd time more likely than not you had primers that weren't fully seated.

The people that keep saying too much crimp will cause this ought to actually try to see just how much crimp it takes to cause the reload to seat deep enough in the chamber to cause misfires. It only takes one time experimenting with how much crimp it takes to actually cause this & you will not here the "too much crimp" thing again.
 
He said the first attempt had NO marks on the the primer, NO impact
Every time I've had a primer fail to go bang because of improper primer seating, there's at least been a small dent in it. I just can't see a primer being seated so far out that it's able to absorb *all* of the firing pin's impact without making at least a small dent. It can only be backed out to the point that it's flush with the bolt face.

IMO, the firing pin never made contact with the primer at all. So that means either something stopped it (as you said), or it couldn't reach it.
 
I looked carefully and found a small dent on the face of the primer.

Photos here as requested.. Thanks for all the comments

9mm FOTO.jpg
 

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Looks like the gun has an inertia firing pin. The pin should make contact with the primer, soon or later, if like my 1911.

The firing pin block , if not correct can slow the pin on firing. The Colt series 80 had 3 different levers that allowed different amounts of travel. The lever pushs on the block.

May need a factory adjustment?
Just my guess. 20191209_161318.jpg

Fire a box of factory ammo. Post results.
 
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i do think it's the bullet getting jammed into the lands. Is the bullet hard to eject? my bullets that had no primer strike fired when reinserted into the magazine and racked. second time. the bullet may have been set back a bit the second time to allow it to go into full battery and if not going into full battery the first time just mild thumb pressure on the slide was able to make it go into full battery. mine was with a cz97b.

my 9 mm czs: 85 combat, pcr, shadow 2, sp01,p10c and p10f are not picky with ammo and i load up to 1.120 but with 147 gr rn or fps has a different ogive compared to a 115 fmj
 
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