I have been reloading for about 50 years now and have never experienced a problem with primers. In the last month I have had three instances (all the same rifle) where upon firing I immediately smelled powder and upon close inspection I found a pin hole at the outside edge of the primer. The ring around the primer also turns black. These are fairly new cases, some almost new and the pockets were not loose when I loaded them. After depriming the pockets look normal and are still not loose. The loads are stiff but not over maximum and extraction is not difficult nor are other signs of overload present. These are Remington 8mm magnum cases necked down to 7mm. This is a lot of 100 I bought several years ago. The primers are either CCi or Remington magnum primers. Any ideas or questions. I will be loading up another 20 or so for testing this week.
Leaky primers
- Thread starter Elkman
- Start date
Antelope_Sniper
Handloader
- Jan 25, 2008
- 2,618
- 0
So you are shooting a 7mm STW.
What's your exact load?
What's your exact load?
- Thread starter
- #3
clearwater
Handloader
- Feb 5, 2005
- 519
- 340
1. Firing pin issue
Check for physical issues with the firing pin -small burr etc.
2. Pressure Issue
Use a starting load with identical components and see if it still happens.
Use a chrony and compare velocity to load data.
You may be over pressure.
Check for physical issues with the firing pin -small burr etc.
2. Pressure Issue
Use a starting load with identical components and see if it still happens.
Use a chrony and compare velocity to load data.
You may be over pressure.
Antelope_Sniper
Handloader
- Jan 25, 2008
- 2,618
- 0
That's warmer then what I would use for a starting load. I'd back off to around 73gr and work back up and see what happens.
What primers are you using?
What primers are you using?
- Thread starter
- #6
sniper/clearwater
I am appreciating the help. I started at 74 gr. other than the primer issue there are no other signs of pressure. Also the rupture is on the outside edge of the primer not anywhere near where the firing pin strikes. The strike is good, not deep (which would also indicate pressure) and at pretty much dead center. The primers are Remington 9 1/2 M. I have used a load of 81 gr. of H-1000 for 10 or so years and this should actually be similar or less. I am trying to find an accurate load for the AccuBond in this rifle and for some reason the H-1000 does not work well with the AB.
Again keep thinking!
I am appreciating the help. I started at 74 gr. other than the primer issue there are no other signs of pressure. Also the rupture is on the outside edge of the primer not anywhere near where the firing pin strikes. The strike is good, not deep (which would also indicate pressure) and at pretty much dead center. The primers are Remington 9 1/2 M. I have used a load of 81 gr. of H-1000 for 10 or so years and this should actually be similar or less. I am trying to find an accurate load for the AccuBond in this rifle and for some reason the H-1000 does not work well with the AB.
Again keep thinking!
Antelope_Sniper
Handloader
- Jan 25, 2008
- 2,618
- 0
Custom gun or out of the box?
Oldtrader3
Ammo Smith
- Nov 6, 2009
- 8,406
- 6
Elkman, tried to PM you and did not work. Have you tried to inspect inside of cup and/or measure thickness at rupture. I never use Remington primers because of bad problem with misfires years ago, so I don't have any insight. I am trying to think of proactive mechanical things that may relate to your problem.
What is bothering me is that I used to collect coins and bronze cents delaminate sometimes because they don't get the copper/zinc mixture hot enough or mix it well enough and it slakes or delaminates. This in primers could cause mechanical property failure leading to the defect that you are describing. Also, the fact that primer sheet for fabrication is plated may cover defect from finding it through visual inspection. Even a burr on a forming punch could cause this defect.
I would clean and inspect fired primer cups for mechanical failure. Even measure wall thickness, if possible. If this is a manufacturing defect, it would be pretty serious for Cerebrus! Have you got access to a microscope to examine fired primers?
What is bothering me is that I used to collect coins and bronze cents delaminate sometimes because they don't get the copper/zinc mixture hot enough or mix it well enough and it slakes or delaminates. This in primers could cause mechanical property failure leading to the defect that you are describing. Also, the fact that primer sheet for fabrication is plated may cover defect from finding it through visual inspection. Even a burr on a forming punch could cause this defect.
I would clean and inspect fired primer cups for mechanical failure. Even measure wall thickness, if possible. If this is a manufacturing defect, it would be pretty serious for Cerebrus! Have you got access to a microscope to examine fired primers?
Not sure if this is due to the same cause, but I had the same problem with Remington primers a LONG time ago. I had a batch of Remington 9 1/2 primers that I was using in a .244 Remington that did the same thing.
I was using pretty mild loads, but every once in a while, one would pierce along the side.
I contacted Remington, told them the lot, and they said that they knew there was a problem with that batch.
I wound up sending the primers back to Remington and they sent me a check for reimbursement. Seems like I had a brick of the darned things, I know it was several boxes.
I was using pretty mild loads, but every once in a while, one would pierce along the side.
I contacted Remington, told them the lot, and they said that they knew there was a problem with that batch.
I wound up sending the primers back to Remington and they sent me a check for reimbursement. Seems like I had a brick of the darned things, I know it was several boxes.
- Thread starter
- #10
trailrider sent me this picture (near the bottom) and its exactly what is happening to me. Any new ideas?
Elkman,
Check this link out. I had the same thing happen. Look at the photos with the win brass with a pin hole on the side of primer, along with gas leakage.
http://www.noslerreloading.com/phpBB2/viewtopic.php?t=12925&start=0
Charlie I tried to send you a PM do you have your mailbox activated? Mine works Bill
Trailrider thanks again for the picture
Elkman,
Check this link out. I had the same thing happen. Look at the photos with the win brass with a pin hole on the side of primer, along with gas leakage.
http://www.noslerreloading.com/phpBB2/viewtopic.php?t=12925&start=0
Charlie I tried to send you a PM do you have your mailbox activated? Mine works Bill
Trailrider thanks again for the picture
trailrider121
Beginner
- Mar 30, 2009
- 60
- 0
Elkman,
No problem. I sent you an email about what maybe happened, but still no really sure.
Here is the picture:
win brass, with Rem 9 1/2 primer.
No problem. I sent you an email about what maybe happened, but still no really sure.
Here is the picture:
win brass, with Rem 9 1/2 primer.
DrMike
Ballistician
- Nov 8, 2006
- 37,518
- 6,562
The picture would seem to imply an eccentric primer pocket, or at least a point of poor friction between the primer and the pocket. It might be worth retesting your load with a primer that employs a steel cup, such as CCI250 or F215. I have never witnessed this with Remington primers, though the evidence seems fairly clear that there is specific leakage resulting from a failure to seal in at least one locus.
Oldtrader3
Ammo Smith
- Nov 6, 2009
- 8,406
- 6
Elkhunter can remove primer and measure pocket for concentricity.
This has happened with (3) out of how many firings? Inspect brass for ovality or issues with primer pocket. Are you reaming primer pockets or cleaning them with anything but a hand scraper which may leave an linear scratch in the pocket wall for gas migration?
Maybe you will also want to soak some unfired primers with gun oil for a few days and then disassemble them for inspection and measurement? Soak enough to cover incidence of blown primers to make sure statistically that you get one. Be careful, they can cause a fearful wound if detonated. I just am wondering if you have a bad batch, specially since others have had the same problems in the past?
Bill, I tried to PM you and it came right back to me. I contacted the moderators to check my PM for problems. Waiting for answer from Moderators on this.
Charlie
This has happened with (3) out of how many firings? Inspect brass for ovality or issues with primer pocket. Are you reaming primer pockets or cleaning them with anything but a hand scraper which may leave an linear scratch in the pocket wall for gas migration?
Maybe you will also want to soak some unfired primers with gun oil for a few days and then disassemble them for inspection and measurement? Soak enough to cover incidence of blown primers to make sure statistically that you get one. Be careful, they can cause a fearful wound if detonated. I just am wondering if you have a bad batch, specially since others have had the same problems in the past?
Bill, I tried to PM you and it came right back to me. I contacted the moderators to check my PM for problems. Waiting for answer from Moderators on this.
Charlie
