223 Light Primer Strike Puzzle

[mb571]

Hi Folks,
Had some reloaded ammo trouble today at the range.
In the 1500 rounds of reloaded 223, I have had one ftf (forgot the powder) until today.
Since my go to H335 is scarce at the moment, I was running a ladder test with Nosler 55 grain balistic tips and some BL-C(2) that I got for cheap at Canadian Tire. I had 3 of each charge times 8 different charges. 25.8 to 27.6 grains.
Right away there was problems. Heard that click and removed the round to see a light primer strike. Some would fire on the second try, some on the third. After this went on for awhile, I was starting to suspect my Tikka TX3 bolt. So I popped some different ammo in and it all shot as usual.
Back to the Nosler loaded rounds and nothing but trouble. Out of the 24 rounds, about 18 failed to fire on the first try. The primers were (at least I thought) CCI #400 Small Rifle Primers. Back to trying some ammo loaded at a way different date. Again no problem.
What would happen if one day I was head-in-the-clouds and picked up the package of small pistol primers? The CCI trays are identical in colour.
Here is a picture of some of the rounds:
1. Unfired
2. Struck once, ftf
3. Struck twice to fire (lifting)
4. Struck multiple times to fire, flattened
5. Empty slot
6 & 7. Different ammo loaded at a different time

 

[209jones]

If you uniformed the primer pockets, you may have a long tool. Haven`t heard of one yet, they have a stop on them, but.
Issue with firing pin spring or crud in the bolt.
Too short on headspacing.
Some gas guns won`t lock up properly on a lighter load.

 

[Potashminer]

The two cases that I see that you describe as "lifting" can only occur if there is excess headspace when the round went off, so as Post #2 identifies - either you are not completely locked up when firing, or those shoulders have been pushed back much too far when resized for that chamber. Brass case too far ahead - firing pin can't properly reach the primer...

The fourth primer looks flattened, because it is no longer supported by the case head - was pushed out of the case and against the bolt face when that round went off.

 

[bigedp51]

It looks like the primers are protruding on two of the fired cases. To me this means the shoulders were bumped back too far and why and why you are having problems. And the protruding primers on the two middle cases also tells me the loads were on the light side. Meaning the chamber pressure was not great enough to push the case back against the bolt face.

Example the primers on my 30-30 always protrude at the max rated pressure of 42,000 psi.


CHOOSING THE RIGHT PRIMER - A PRIMER ON PRIMERS
http://www.sksboards.com/smf/index.php?topic=56422.0

CCI 400 -thin .020" cup, not recommended for AR15 use by CCI/Speer. Good for .22 Hornet, .30 Carbine. See Note 1 at the bottom of the page

NOTE 1: According to Speer/CCI Technical Services - Both the CCI 550 Small Pistol Magnum and CCI 400 Small Rifle primers are identical in size. Both primers use the same cup metal and share the same cup thickness. Both primers use the same primer compound formula and same amount of primer compound. They can be used interchangeably.

The amount of shoulder bump on a resized case will be your head clearance when the cartridge is chambered. And at lower chamber pressures the primers will protrude when fired. If you make a workup load starting at the suggested start load and work up you will see the primers protruding. And the primers will continue to protrude until the chamber pressure increases and pushes the case back into the bolt face.

Below protruding primers on a low pressure load.

 

[Ganderite]

Are bullets touching the rifling? That can cause a misfire.

 

[Dogleg]

Protruding prmers without flattening are from excess head space and low pressure. Protruding primers with flattening are from excess head space and normal or high pressures. Primers the size of belt buckles but flush are high pressure and loose headspace.

Excess head space can be created on the bench.

 

[Janeau]

Protruding prmers without flattening are from excess head space and low pressure. Protruding primers with flattening are from excess head space and normal or high pressures. Primers the size of belt buckles but flush are high pressure and loose headspace.

Excess head space can be created on the bench.

+ 1 on this.
Your sizing die is pushing the shoulder too much, this is creating excess headspace.
Accumulation of lube or crud in the sizing die can also be a factor.
Mixed head stamp brass of different lot are not all the same hardness and not resize uniformly.

You primers might not be seated properly - if not seated to the 3 prongs of the anvil are not compressed, the firing pin blow will be dampened.

The problem is in your reloading process. Get a headspace gage like the Hornady tool - there is better - but this will do and make sure you are not bumping the shoulder more than .002 - .004 max. Just adjusting you sizing die fully in, touching the shellholder is not the way to do it.

 

[DuckTape]

Hi,
There is a possibility that the primer detonated without any powder in the case.
I would suggest removing the bullet to check this out.
Regards

 

[toddpotiphar]

Hi,
There is a possibility that the primer detonated without any powder in the case.
I would suggest removing the bullet to check this out.
Regards

Detonation of primer without powder in the case should provide pressure sufficient to remove the bullet from the case and lodge it in the throat of the barrel. (I've done it on only one occasion, but hopefully that's enough.)

 

[mb571]

Are bullets touching the rifling? That can cause a misfire.

Definitely not. Jam length is 2.315" and loaded to fit the Tikka magazine: 2.850"

 

[mb571]

Hi,
There is a possibility that the primer detonated without any powder in the case.
I would suggest removing the bullet to check this out.
Regards

I don't believe this is the case. To re-state some of the facts: It happened for about 18 of the 24 rounds but many of them fired after a 2nd or 3rd try.

 

[mb571]

+ 1 on this.
Your sizing die is pushing the shoulder too much, this is creating excess headspace.
Accumulation of lube or crud in the sizing die can also be a factor.
Mixed head stamp brass of different lot are not all the same hardness and not resize uniformly.

You primers might not be seated properly - if not seated to the 3 prongs of the anvil are not compressed, the firing pin blow will be dampened.

The problem is in your reloading process. Get a headspace gage like the Hornady tool - there is better - but this will do and make sure you are not bumping the shoulder more than .002 - .004 max. Just adjusting you sizing die fully in, touching the shellholder is not the way to do it.

Thanks for this response. A lot that makes sense in it.
I sort the brass by headstamp. Trim to the same length. Clean in a wet tumbler with ss pins. I sort all the cases by weight...so same headstamp, length and weight. When seating primers with my Frankford Arsenal hand seater, I adjust depth till there is a small crease on the primer and then back off a couple clicks.
You may be onto something in regards to hardness. I had full length re-sized these cases a long time ago. I decided to anneal the necks and then neck sized with a Lee collet die. There is a chance that I over annealed them?? Too bad I can't just run over to our local store and grab a headspace gauge....it burned down over the Christmas holidays and many online joints are struggling with stock, so when you go to buy enough to get free shipping or make it worth your while, it is hard to find all the bits you need.
Edit: Lyman at Cabelas or Hornady on amazon.ca. Preferences for a headspace gauge?

 

[remington jim]

Definitely not. Jam length is 2.315" and loaded to fit the Tikka magazine: 2.850"

Your Jam lenght has Nothing to do with your Mag lenght ! You should be around a 2.260 -2.270 COAL for that rifle with that bulletand feed grom the mag ! RJ

 

[mb571]

Your Jam lenght has Nothing to do with your Mag lenght ! You should be around a 2.260 -2.270 COAL for that rifle with that bulletand feed grom the mag ! RJ

I was responding to the statement "Are bullets touching the rifling? That can cause a misfire." I was stating that I was shooting with a 0.035 jump. And 2.280" will load from my mag. That particular bullet could be loaded to 2.300, if single loaded (0.015 off the rifling). At 2.260", it is a 55 thou jump. Too far in my opinion (although the Tikka chamber seems to manage the longer jump okay).

 

[Dogleg]

Here’s something that might fit in here somewhere; seeing as light strikes were mentioned.

People will compare the firing pin indent of a misfired case to one that fired nd conclude that they look the same. The mistake there is its not the same scenario. The pin drop on the fired case met a miniscukle scrap of brass, some hardened primer compound and somewhere around 60,000 psi of force that pushes back, squares things up and imprints to the pin tip. Without the pressure a good hit looks more like a funnel. If it looks sort of like the primer from a fired case it was pretty wimpy.

 

[HondaVTEC]

Excessive head space caused by the shoulder being pushed back too far . Been there .

 

[mb571]

Excessive head space caused by the shoulder being pushed back too far . Been there .

And how did it come to that? What kind of sizing die?
And how did you resolve it?
Mark

 

[Leeper]

To set up your sizing die, start with a case which has been fired in the rifle with a load which produces normal pressure. A factory load is perfect.
Now, screw your sizing die into the press. With the ram all the way to the top and the shellholder in place, screw the die down until it touches the shellholder then, back it out about 1/2 turn. Size the case and try it in the rifle. It should close but with noticeable resistance. Now, turn the die in 1/8 turn and size again. Try in the rifle. Repeat this until the bolt closes with just very light resistance. Lock the die here and this will be your sizing die setting from now on.

 

[ruger-ruger]

Are bullets touching the rifling? That can cause a misfire.

How does a bullet jammed into the rifling cause a miss fire??
First time I have heard that.

I do it lots for forming wildcat brass to some of my guns like the bullets tight in the lands. Not going to cause a misfire.

 

[Dogleg]

On a standard 7/8 -14 thread an 8th of a turn would work out to:

1” divided by 14 divided by 8 = .0089” which a reasonable person might round off to 9 thousandths. Thats sort of like measuring with a micrometer and cutting with a chainsaw . Far better is to sneak up on it with a set of Redding Competition shell-holders. Thats a fight someone could win.