Punctured Primers Help Please!

S

stanley52

Private
Full Member
Minuteman
Aug 10, 2013
91
3
Idaho
#1
Ok so I have a 280 AI that I have developed some fantastic loads for, but I continually puncture primers. My original load was 60.1gr H4831sc 168gr bergers, and CCI 200's, and there were no pressure signs except I kept puncturing primers. I sent my bolt in and had it bushed, still getting some punctures, so I dropped the charge to 58.5 which is only .5 above Nosler load data max. Still punctured primers, although the hole is smaller. I say again 0 pressure signs other than punctured primers with either loads. I haven't remeasured the firing pin protrusion but it was bushed by Score High so I'm sure that it is fine. There has also been several misfires and they were definitely not light strikes. The bushed firing pin/firing pin hole punches some pretty deep holes. I called CCI and a tech told me to switch to their BR2 primers, he said they had a thicker cup? Everything I have ever read or heard says they have the same cup, and are just held to better quality control. Maybe the material is better? Any thoughts on this? I have also heard magnum primers are tougher. If anyone has some advice please share.. Thanks ahead of time. Can't post pics right now, can on Sunday.
 
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#2
What's the pin tip profile look like? Can you remove the pin assy and take a close up side profile picture of the tip showing the radius on the tip? What is the pin protrusion? You say you have had some misfires, how much pin fall do you have?
 
#4
Aeon1 said:
What's the pin tip profile look like? Can you remove the pin assy and take a close up side profile picture of the tip showing the radius on the tip? What is the pin protrusion? You say you have had some misfires, how much pin fall do you have?
Click to expand...

I won't have access to my rifle again till Sunday, then I can answer some of these questions.
 
#9
rjacobs said:
Did you read his post at all? He mentions having the bolt bushed 3 times.

I will though agree that maybe the firing pin is a bit wonky.
Click to expand...

Firing pin is a bit wonky? I'm not sure if I'm tracking man, can you elaborate? I appreciate all the responses and help. Not trying to get upset with anyone over a simple oversight from my OP.
 
#10
stanley52 said:
Firing pin is a bit wonky? I'm not sure if I'm tracking man, can you elaborate? I appreciate all the responses and help. Not trying to get upset with anyone over a simple oversight from my OP.
Click to expand...

to long(and thus the protrusion is to much), to sharp, burr on it, etc... Lots of things that COULD cause what is happening. I'm not a bolt gun expert, but I am sure somebody will be by shortly that can help get you squared away.
 
#12
Dan Newberry said:
Have you tried different primers? Maybe a bad lot... or someone switched pistol primers out on ya... with component supply problems it's hard to tell what might happen out there.

The misfires are potentially another clue to a bad batch of primers.

Dan
Click to expand...

I have not tried new primers yet because I didn't know if it was the primers, the charge, or the firing pin. I didn't want to spend more money on primers when I had 2000 200's already.. A tech at CCI said to try their BR2's to help fix punctures but he was literally the only person I have ever heard say BR2's are tougher than 200's. And yes I agree.. 4 misfires in 40 is way too many. No pics right now, but it was a turned pin so it was a smaller hole, but very deep and it caved the primers in a good bit... No reason they shouldn't have fired.
 
#16
This is a shot in the dark, but have to checked the headspace on ALL your rounds? If the headspace is a bit excessive, you can get failure to fires and also can get pierced primers. The primer getting slammed back against the FP during ignition, instead of being supported by the boltface can result in pierced primers.
 
#17
buffybuster said:
This is a shot in the dark, but have to checked the headspace on ALL your rounds? If the headspace is a bit excessive, you can get failure to fires and also can get pierced primers. The primer getting slammed back against the FP during ignition, instead of being supported by the boltface can result in pierced primers.
Click to expand...

buffybuster, you hit the nail on the head with the right answer.

stanley52, you need to measure your fired cartridge heaspace and your resized case headspace length. It sounds like your bumping the shoulder of the case back too far and creating excessive head clearance or air space between the rear of the case and the bolt face.

Watch the animation below of a cartridge firing and "primer movement".

HeadClearance_zpsf30a3af1.gif


Head clearance is the distance from the bolt face to the rear of the case, and this is how far the primer can move to the rear when the cartridge is fired.

HEADCLEARANCE-a_zps53089f07.jpg


After the firing pin hits the primer and fires the cartridge chamber pressure forces the primer out of the primer pocket and "BACK OVER" the firing pin. When you have excess head clearance the primer can move further to the rear and as it flows back over the firing pin the primer hit is punched out just like a cookie cutter.

piercedprimer-1_zps292b54b8.jpg


This is just "one" reason why the military crimps its primers because of the longer headspace settings (head clearance) on military firearms.


primersa-1_zps144ecb5f.jpg
 
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#19
Almost all large rifle primers have a cup thickness of .027 and made to withstand well over 60,000 psi. Yes changing primers might help BUT so is not bumping the shoulder back excessively. In most cases the problem is caused by over resizing your cartridge cases and excessive head clearance.

calhoonprimers02_zpsb8295b11.png


The OP needs to be measuring cartridge headspace after the case is fired and after resizing for correct shoulder bump.

gauge002_zpsd2792ffa.jpg
 
#20
Yes, incorrect full length resizing can explain pierced primers, but there are other reasons. To say "no pressure signs" when you have pierced primers is probably not true. My question is how did you develop your load: "60.1gr H4831sc 168gr bergers" while "continually" piercing primers? I would have stopped with the first pierced primer because something is wrong, and continuing to fire X number of loads that pierce primers will certainly damage the bolt face. That's all I have to say; you need to get to the bottom of it, (and your solutions have merit) but pierced primers calls for a complete reevaluation. I'm not sure when you say, "still getting some punctures"? Does this mean random or occasional or all primers are pierced? Did you ever have a situation with this particular load that you did not pierce primers? I don't understand how you arrived at 60.1 grains in your workup without experiencing the same problem along the way....unless you just picked a load without starting by reducing a book charge by 10% or so? No offense, but. I'm questioning your load development technique? BB
 
#21
buffybuster said:
This is a shot in the dark, but have to checked the headspace on ALL your rounds? If the headspace is a bit excessive, you can get failure to fires and also can get pierced primers. The primer getting slammed back against the FP during ignition, instead of being supported by the boltface can result in pierced primers.
Click to expand...

I learned this the hard way and so many people over look this when they start getting pierced primers. I didn't believe it at first, but after trying new brass with the same load I was convinced. There were absolutely no pressure signs with the new brass.
 
#22
bigedp51 said:
buffybuster, you hit the nail on the head with the right answer.

stanley52, you need to measure your fired cartridge heaspace and your resized case headspace length. It sounds like your bumping the shoulder of the case back too far and creating excessive head clearance or air space between the rear of the case and the bolt face.

Watch the animation below of a cartridge firing and "primer movement".

HeadClearance_zpsf30a3af1.gif


Head clearance is the distance from the bolt face to the rear of the case, and this is how far the primer can move to the rear when the cartridge is fired.

HEADCLEARANCE-a_zps53089f07.jpg


After the firing pin hits the primer and fires the cartridge chamber pressure forces the primer out of the primer pocket and "BACK OVER" the firing pin. When you have excess head clearance the primer can move further to the rear and as it flows back over the firing pin the primer hit is punched out just like a cookie cutter.

piercedprimer-1_zps292b54b8.jpg


This is just "one" reason why the military crimps its primers because of the longer headspace settings (head clearance) on military firearms.


primersa-1_zps144ecb5f.jpg
Click to expand...

I have not FL resized this brass. I have only neck sized it, so I doubt headspace is the issue. But idk..
 
#23
BuzzBoss915 said:
Yes, incorrect full length resizing can explain pierced primers, but there are other reasons. To say "no pressure signs" when you have pierced primers is probably not true. My question is how did you develop your load: "60.1gr H4831sc 168gr bergers" while "continually" piercing primers? I would have stopped with the first pierced primer because something is wrong, and continuing to fire X number of loads that pierce primers will certainly damage the bolt face. That's all I have to say; you need to get to the bottom of it, (and your solutions have merit) but pierced primers calls for a complete reevaluation. I'm not sure when you say, "still getting some punctures"? Does this mean random or occasional or all primers are pierced? Did you ever have a situation with this particular load that you did not pierce primers? I don't understand how you arrived at 60.1 grains in your workup without experiencing the same problem along the way....unless you just picked a load without starting by reducing a book charge by 10% or so? No offense, but. I'm questioning your load development technique? BB
Click to expand...

Ok to clarify, I worked up to 62.5gr when I was doing max pressure tests and that was when I pierced my first primer, so I backed off and found a node at 60.1, there were no pierced primers with it at first. When I loaded about 30 of this load up for a some more testing I occasionally pierced them, then it got a little more frequent. I then sent my bolt in to be bushed and the pin turned. I had fewer pierces but there were still some, so I backed off to 58.5 and am still having some. The holes are not nearly as gaping now, they are a normal strike with a tiny little pierce in the bottom of the strike. I still have probably 2/10 pierced with 58.5gr and a bushed bolt/turned pin. I think I'm going to polish the pin down a few thousandths and blunt the curve a bit and use the BR2's. I just don't know what else it could be, since I have not FL sized the brass. This is all 2-3 time fired brass so headspace couldn't be an issue..
 
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#24
Well, thanks for the clarification and plugging in a few pertinent facts. Perhaps the Peanut Gallery could be persuaded to reevaluate the diagnosis? Any fresh ideas? BB
 
#26
I think you shouldn't do anything else to the rifle before trying another batch of primers. We're seeing more bad primers these days then ever before. You used to never see bad primers... and now, it's almost the norm, especially with CCI's... I see thousands of shots fired a month (from match shooters, long range students)... and the CCI's have indeed been giving trouble in various guns, and from various lots.
 
#27
Dan Newberry said:
I think you shouldn't do anything else to the rifle before trying another batch of primers. We're seeing more bad primers these days then ever before. You used to never see bad primers... and now, it's almost the norm, especially with CCI's... I see thousands of shots fired a month (from match shooters, long range students)... and the CCI's have indeed been giving trouble in various guns, and from various lots.
Click to expand...

Switched to BR2's and fired 10 shots.. No punctures. I think I found the solution. Must have been a bad batch or perhaps BR2's are tougher as the tech claimed... Idk
 
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#29
former naval person said:
Small hole, very deep, and the piercing is at the extreme depth? I'd check FP protrusion. Maybe turned too small and pointy. JMHO
Click to expand...

Yeah even though the BR2's have seemingly fixed the issue, I may polish the tip down just a a couple thousands to blunt it a touch because it does look fairly sharp to ensure this problem does not persist if I had to use other primers again... In case the 200's weren't just a bad batch and the BR2's are structurally tougher.
 
#30
stanley52 said:
Yeah I had a 32lb Wolff Blitzschnel spring put in
Click to expand...

Assuming this is a Remington 700 why would you ever need/want a 32lb spring?

While on the topic are you using a factory pin or an aftermarket lightweight pin?

When you take the pin out to modify it get a picture of it before you change it, I'm curious to see the profile.
 
#31
Aeon1 said:
Assuming this is a Remington 700 why would you ever need/want a 32lb spring?

While on the topic are you using a factory pin or an aftermarket lightweight pin?

When you take the pin out to modify it get a picture of it before you change it, I'm curious to see the profile.
Click to expand...

Will do, and I truthfully don't know why, that is just what Charlie at Score High put in it. It is a factory steel pin.
 
#34
Hard to tell with that picture, looks like some reflections are distorting what's really there. Is the Timney a standard trigger like a 510 (not a 510-U). Let us know what the pin protrusion and pin fall is. Looking forward to better pictures.
 
#35
stanley52 said:
I called CCI and a tech told me to switch to their BR2 primers, he said they had a thicker cup? Everything I have ever read or heard says they have the same cup, and are just held to better quality control. Maybe the material is better? Any thoughts on this?
Click to expand...

I spoke with CCI today and they told me the same thing. Maybe we spoke to the same guy? I too have used CCI 200s and BR2s interchangeably believing they have the same cup thickness. He told me the 200s have the "standard cup" and the BR2s, 250s, and military primers have the "thick" cup. He said the exact measurements were proprietary but he did say the chart floating around the internet (and referenced in the thread) is INCORRECT as far as CCI primers are concerned.
 
#36
Known said:
I spoke with CCI today and they told me the same thing. Maybe we spoke to the same guy? I too have used CCI 200s and BR2s interchangeably believing they have the same cup thickness. He told me the 200s have the "standard cup" and the BR2s, 250s, and military primers have the "thick" cup. He said the exact measurements were proprietary but he did say the chart floating around the internet (and referenced in the thread) is INCORRECT as far as CCI primers are concerned.
Click to expand...


This is kind of a late update, but this information is correct. I switched to the BR2's like he suggested and have not had a punctured primer since.
 
#39
Known said:
I spoke with CCI today and they told me the same thing. Maybe we spoke to the same guy? I too have used CCI 200s and BR2s interchangeably believing they have the same cup thickness. He told me the 200s have the "standard cup" and the BR2s, 250s, and military primers have the "thick" cup. He said the exact measurements were proprietary but he did say the chart floating around the internet (and referenced in the thread) is INCORRECT as far as CCI primers are concerned.
Click to expand...

FLIGHT762 said:
Interesting about the BR2's. Hadn't heard that. The CCI tech should know. With that information, I wonder how well the BR2's will do in a 308 / 30/06 gas gun?
Click to expand...

I would suspect they would perform well both with firing pin strikes and ignition. They seem to be every but as sturdy as the 250's
 
#40
Known said:
I spoke with CCI today and they told me the same thing. Maybe we spoke to the same guy? I too have used CCI 200s and BR2s interchangeably believing they have the same cup thickness. He told me the 200s have the "standard cup" and the BR2s, 250s, and military primers have the "thick" cup. He said the exact measurements were proprietary but he did say the chart floating around the internet (and referenced in the thread) is INCORRECT as far as CCI primers are concerned.
Click to expand...

Known said:
That is VERY encouraging news...
Click to expand...

Dude I know the feeling.. It was driving me insane when I kept puncturing primers when everything about my load/rifle checked out.
 
#44
Known said:
I spoke with CCI today and they told me the same thing. Maybe we spoke to the same guy? I too have used CCI 200s and BR2s interchangeably believing they have the same cup thickness. He told me the 200s have the "standard cup" and the BR2s, 250s, and military primers have the "thick" cup. He said the exact measurements were proprietary but he did say the chart floating around the internet (and referenced in the thread) is INCORRECT as far as CCI primers are concerned.
Click to expand...

Known said:
They will not work on an Accuracy International bolt.
Click to expand...

Try Charlie at Score High Gunsmithing in Albuquerque. He bushed/turned my rig and it stopped any shred of primer cratering. If that's Br2's don't fix it, maybe try giving him a call and seeing if he'll work on an AI bolt
 
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