Firing pin appears to be piercing primer

[skipglo]

Occasionally speed isn't always what a rifle likes. Just my 2c

X2...just pointing out where over pressure could exist !

 

[MagnumManiac]

Another point that has been mentioned, but no real detail given regarding an oversize firing pin hole, is that bushing it AND reducing the diameter of the firing pin is often the only fix. If you just bush the hole with the same size firing pin, it can sometimes not fix the issue.
I know it sounds strange, but it is the diameter of the firing pin that MAY be causing the issue too.
I have done this on my SRP cartridge rifles as a failsafe because I know a normal firing pin diameter can cause issues on SRP and blank them WITHOUT excessive pressure.
So, my 2 6.5x47's, my 22-250AI, 260AI and 7-08 are all running smaller firing pin diameters for the SRP brass.

Cheers.

 

[cajun]

Thanks for all of the information and comments. All constructive toward finding a resolution to this issue as well as educating me on this reloading circumstance.

The rifle and brass will go to the gunsmith next week for complete inspection.

All of the loads were for load development, so no residual remains. I will start over completely with the load development.

The load for this rifle that resulted in the damaged primers was 3 shots chrono'd with a Garmin at 3110 fps average with 42.5 of H4350.
Attached is the Hornady load data on the 103 ELD-X, basically their "red" load is 43.9 grs H4350 with 3150 fps.

In any case, it appears that this load at 42.5 is too hot for those primers in this rifle. Unless there is a mechanical issue which I will get resolved next week.

You read that wrong. The 43.9 is for the other 100 gr bullets. The eldx has a longer bearing surface and it's load data is below that at 42.2 max. Fyi nosler data maxes out at 40.5 for 100's and 39.5 for a 105.

 

[RB II]

You read that wrong. The 43.9 is for the other 100 gr bullets. The eldx has a longer bearing surface and it's load data is below that at 42.2 max. Fyi nosler data maxes out at 40.5 for 100's and 39.5 for a 105.

You are right. My mistake.

 

[Dean2]

You read that wrong. The 43.9 is for the other 100 gr bullets. The eldx has a longer bearing surface and it's load data is below that at 42.2 max. Fyi nosler data maxes out at 40.5 for 100's and 39.5 for a 105.

Well, that would explain the pierced primers pretty easily.

 

[cajun]

It could very well be a combo of a slightly over pressure load, thin cup primers and a firing pin issue. I wonder during load work did you see any issues before this?

 

[RB II]

It could very well be a combo of a slightly over pressure load, thin cup primers and a firing pin issue. I wonder during load work did you see any issues before this?

This was my first round of load development for this rifle. I just got it a couple weeks ago and took it to be bedded.

 

[cajun]

You could reduce this load 1 to 1 1/2 grains and fire a few rounds. If the primers are still an issue it's likely the firing pin.

 

[RB II]

Well, that would explain the pierced primers pretty easily.

I didn't load to the 43.9 grs, my highest load was 42.5. I just misread the Hornady chart that I dug up for some info on this thread. Actually the Hornady and the Hodgdon charts are less than 1/2 grain difference in their respective max loads. The bullet is Hornady and the powder is Hodgdon.

 

[cajun]

I didn't load to the 43.9 grs, my highest load was 42.5. I just misread the Hornady chart that I dug up for some info on this thread. Actually the Hornady and the Hodgdon charts are less than 1/2 grain difference in their respective max loads. The bullet is Hornady and the powder is Hodgdon.

You are just slightly over the Hornady load. But Christensen has been known to put out some tight chambers that pressure out early. If you reduce the load and or try some 450's you can rule out the load or primer issue.

 

[RB II]

I am going to get it inspected next week. Have 450s on order and when they come in I will load more with them, starting around 41 grs.

 

[Dean2]

I am going to get it inspected next week. Have 450s on order and when they come in I will load more with them, starting around 41 grs.

I would strongly suggest starting at 38 and work your way up .5 grain at a time, given the problems you have already had. Measure the velocity of each load and analyse the fps gain for each .5 grains of powder added. If you get to a spot where the gain is less than half the extra fps of the previous load gains, or worse zero gain, stop.

 

[lyle2231]

I would strongly suggest starting at 38 and work your way up .5 grain at a time, given the peoblems you have already had. Measure the velocity of each load and analyse the fps gain for each .5 grains of powder added. If you get to a spot where the gain is less than half the extra fps of the previous load gains, or worse zero gain, stop.

The Sierra manual. has always been a consistent reference for me. I usually start with the middle load and work my up according to the information on the recipe page.

 

[lyle2231]

Thanks for all of the information and comments. All constructive toward finding a resolution to this issue as well as educating me on this reloading circumstance.

The rifle and brass will go to the gunsmith next week for complete inspection.

All of the loads were for load development, so no residual remains. I will start over completely with the load development.

The load for this rifle that resulted in the damaged primers was 3 shots chrono'd with a Garmin at 3110 fps average with 42.5 of H4350.
The Hornady load data on the 103 ELD-X, basically their "red" load is 43.9 grs H4350 with 3150 fps.

In any case, it appears that this load at 42.5 is too hot for those primers in this rifle. Unless there is a mechanical issue which I will get resolved next week.

I would back off to 39 grains and start over. .
IMHO you're starting too hot! Work up in .3 - .5
grain increments. HTH