CCI BR4 and 450 primer problems

[Rocketvapor]

Now, I take you back to the OP's problem, which is piercing CCI450 primers.
He could change primers, or try and figure out what is going on.
We have beat the horse into submission with that old drawing and all kinds of issues with CCI450 Primers.

 

[rwj]

 

[Rocketvapor]

@deadidarren
Bolt or AR?
How do you determine headspace and sizing bump?

 

[dgeesaman]

The drawing is incorrectly dimensions!!

The base and wall thickness can be accurately measured using Mic attachments!! See pic below!!! Yes there is a slight error using the knife edges on small radii called secant to cord error!!! But accuracy was not the issue!!!

As an engineer, you have to learn to set tolerances!! I will say this, the reloader does not need to exceed one thousandth of an inch in measuring anything!!! I see some forum members with digital neck thickness C-Mics that read to one ten thousandth of an inch. The slightest taper and irregularities inside the neck are much greater than 0.0001". If your going to use measuring devices with that much accuracy, you had better be in a climate controlled environment with the sample(s)

That’s fun I’m also an engineer and I’ve been designing and drafting my own work for 25 years now. I dabble in metrology too.

Anyway you keep harping on about an incorrect drawing. I have never seen a manufacturing drawing for a primer. So I have no idea what your gripe is about parts not to tolerance and not per ISO drafting standards. You’ll need to share this manufacturing drawing or drop it.

 

[deadidarren]

OK, here's my measurement results I've just completed :

I took a new primer, removed the anvil, cleaned the primer compound out for a Rem 9 1/2 and for a CCI-450.

The 9 1/2 overall height measured .1185". Measuring into the bottom of the cup from the top measured .0905. .1185-.0905=.028, which is pretty close to the chart's stated spec. The primer wall measured .016".

The CCI-450 measured .1125 in overall height. Measuring inside to the bottom of the cup measured .0865. .1125-.0865=.026. Again, that's pretty close to the chart's stated spec. The primer wall again measured .016".

The walls on the primers ARE NOT the same thickness as the bottom of the cups.

BTW: The Rem 9 1/2 cup weighed 3.5 grs and the CCI-450 cup weighed 2.52 grs; anvils weighed 1.18 and .84 grs respectively. I didn't think of weighing them before I started to see just how much the compound weighed.

Well thank you for your efforts I appreciate it very much .
It's a good day as I have learnt something.

 

[deadidarren]

@deadidarren
Bolt or AR?
How do you determine headspace and sizing bump?

Ok it's a bolt and I neck size only it is a mild load as far as I am concerned as I can load a case approximately nine times before I have to bump the shoulder back a couple of thou.
Velocity is 2742 feet per second and someone mentioned the maximum load for a 55 gr bullet was 25 grains I am assuming that is because lack of space in the case as ADI who are the manufacturers of varget we know it here is AR2208 say 25 grains is a max load for a 75 grain projectile that is at around 48,000 Cup .
Projectile is seated 0.007" off the lands .

 

[Rocketvapor]

Great info.
Now the armchair experts can offer troubleshooting advice, and ask more questions.
What percentage of 450/BR4 primers pierce?
Did this just start with a primer change?
What previous loads worked without problems?
450/BR4 might produce a little more pressure than say CCI400, or WSR.

Got pictures of blown/pierced primers?

I'll back out now and let the experts fix your prob

 

[Wild Bill IV]

That’s fun I’m also an engineer and I’ve been designing and drafting my own work for 25 years now. I dabble in metrology too.

Anyway you keep harping on about an incorrect drawing. I have never seen a manufacturing drawing for a primer. So I have no idea what your gripe is about parts not to tolerance and not per ISO drafting standards. You’ll need to share this manufacturing drawing or drop it.

If you want ISO drawings, do a search of NATO SPECs drawings!!! They will be in ISO specs (metric)! I spent 2hr last night looking for ANSI drawings since the generic drawing was America STD (inches)!!!

Both of us were decisive with your OP generic drawing!! And yes, I accurately measured a BR-4 primer and had almost the same figures as another post! Exempt, I neutralized the active compound with oil for safety concerns before removing the anvil and the muddy grey compound! Yep, heavy metal (possibly lead) based compound!! The mud looked like paste mix for leads acid batteries!! Could be PbIIO2 or PbO lead oxides!!!

Now that we both know the thickness isn't the issue, pictures of the pierced primers would be helpful!!! Some factors that cause piercing of primers are:

- excessive pressure
- bad squib loads
- improper primer seating
- loss primer pocket
- sharp protrusion on the primer seater face
- chipped or fractured primer seater
- sharp protrusion on the firing pin
- chipped or fractured firing pin
- over traveling firing pin
- protruding locked firing pin
- foreign particle(s) embedded in the bolt face
- sharp protrusion(s) on the breach end of the magazine(s)
- sharp protrusion(s) on the bolt when feeding a round

If you find the cause, please share the results with all of us interested and concerned forum members!!

Aim small, hit BIG!!!!!!!!
Bill

 

[Doom]

What is the condition of the primers that didn't pierce? Is there flattening or cratering? If they don't exhibit an issueI I seriously doubt that the primer is the issue. Going from no issue to piercing with the same batch of primers points to another issue. I suspect that either your powder measurement is in error OR because you are trying to seat 7/1000ths off the lands some of you rounds are into or extremely close to the lands leading to a spike in pressure.

 

[bozo699]

What is the condition of the primers that didn't pierce? Is there flattening or cratering? If they don't exhibit an issueI I seriously doubt that the primer is the issue. Going from no issue to piercing with the same batch of primers points to another issue. I suspect that either your powder measurement is in error OR because you are trying to seat 7/1000ths off the lands some of you rounds are into or extremely close to the lands leading to a spike in pressure.

Or a carbon ring
Wayne

 

[Wild Bill IV]

Or a carbon ring
Wayne

You're onto something Wayne!!
Could also be too long a neck!

 

[deadidarren]

Well don't I feel like an idiot.
Last week I lent my son a mtm ammo box so he put his ammo in it and didn't remove the labels that I put on them with the load data and I grabbed the wrong box out of the cabinet.
Soooo problem solved .
And as for a carbon ring we'll let's just say as a verget user I am well versed in removing them .
Thanks for all the work fellers I appreciate it .

Cheers Darren

 

[powderbrake]

Wild Bill IV says the drawing is wrong. From a design, specification, or manufacturing drawing standpoint he is 100% correct.
What we have here is a typical information drawing as might appear in a gun magazine, which implies the walls are the same thickness as the base. It is the one that is "wrong", but the people who produced that drawing don't care about the wall thickness.

I have watched primers being stamped out, and it is difficult to draw a cup without thinning the walls, as the center punch tends to hold the material of the base in place and the walls have to extrude up from whatever was the disk size before drawing.

The real problem here is that magazine writers, and other non technically trained writers or graphic artists, do not know all the "rules" of engineering drawings, so don't count on their accuracy. If the description of the dimension had said "cup base thickness" it would have been "more" correct.

 

[Rocketvapor]

Darren,
Glad you figured this out.
Could you esplain the difference in load that was piercing primers?

Gee, now we all know the likely TRUE dimensions of the thicker CCI primers.
Wonder what a cross section of the Thinner Cup primers looks like?

 

[Wild Bill IV]

Well don't I feel like an idiot.
Last week I lent my son a mtm ammo box so he put his ammo in it and didn't remove the labels that I put on them with the load data and I grabbed the wrong box out of the cabinet.
Soooo problem solved .
And as for a carbon ring we'll let's just say as a verget user I am well versed in removing them .
Thanks for all the work fellers I appreciate it .

Cheers Darren

Thank you Darren for letting us know what the problem was!!! Never would have suspected mix batch error!!!

Good luck
Bill

 

[Wild Bill IV]

Darren,
Glad you figured this out.
Could you esplain the difference in load that was piercing primers?

Gee, now we all know the likely TRUE dimensions of the thicker CCI primers.
Wonder what a cross section of the Thinner Cup primers looks like?

Don't go there!!!!
I'm not suiting up for this game!
I'll watch it from the bleachers!!!

 

[markm87]

I loaded some 5.56 ammo using 75gr RMR, TAC, and my CCI #41s. Shot them Sunday in front of the Garmin and got an ES of over 100 fps, and an SD of over 42.

These CCIs continue to be absolute chaos.

 

[Rocketvapor]

WSR, 0.021" per the diagrammy, CCI450 0.025".
I did not measure.

 

[RegionRat]

Nice photo Rocketvapor.

That pretty much shows that there are some differences in the primer cup sections intended to accommodate the expected pressure differences in the intended applications.

The OP's error was a mix-up of the ammo boxes and had nothing to do with primer designs in the end.

@markm87 a short goal for an AR15 of an SD nearer to 15 is fair for a 556 load using 75 - 77 grain bullets. (In a bolt rig, you can do better with some luck.)

If you have ever had this recipe down less than your present SD of 42 using your current component batches, then now would be the time to try the other primers again. That exercise does tend to isolate the primer in the grand scheme of things, or it could also show that something else is the cause.

If however you have never had this particular recipe down nearer to 15, then you will have to keep all channels open and not just focus on the CCI 41 primer as a component or root cause. You want to try and avoid prematurely blaming the CCI 41 in case it isn't really your issue.

The 223/556 is one of the more difficult cases to achieve good velocity stats. But by the way, unless you are using this to compete out past 400 yards, the good news is that you probably can relax and just worry about the targets while you investigate.

The reason not to prematurely blame the CCI 41is that there is a very long history with ammo and competition that shows all AR friendly primers (including the 41) have been used successfully to produce good velocity stats with 75 - 77 grain loads, even in mass production where more of that speed stat tolerance is given to the charge and powder tolerance.

It isn't impossible that your batch of primers is to blame, but to isolate that to the primer batch or specifically to the 41 will take work and if the real problem is something else you benefit from knowing it. Good Luck, in for the range reports.

 

[markm87]

@markm87 a short goal for an AR15 of an SD nearer to 15 is fair for a 556 load using 75 - 77 grain bullets. (In a bolt rig, you can do better with some luck.)

I can usually get close to 10 with Wolf SRMs. sometimes lower. Pretty much anything I load stays under 20.

But this batch of primers is all over the place. I'm going to have to shoot another string this weekend.