Over sized firing pin hole?

hunter24605

Handloader
Apr 30, 2016
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3,576
I'm seeing what appears to be cratering with CCI primers. Although the primers themselves are not pancaked and still have a radius profile..I never really thought much about them until a friend looked at them and commented..The loads were .5 grain below book max..This is the same Model 70 I just sent back to Winchester with a sticking firing pin and safety and they they replaced the whole bolt assembly. So looking at the primers, should I be concerned there is a firing pin hole or headspace issue? Still kind of new to reading primers. The bolt face is perfect without any pits or scorch marks.
 

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Primers look good to me. Most of mine look like that honestly with starting loads or top end loads.


Primers are not a reliable way to read pressure.
 
Your primers appear normal. I would assuredly have no concerns with what you are showing.
 
Thanks, that's good to hear. The little ridge around the primer strike dimple was concerning. I was told that you should run your fingernail across your primers and if it "snags" that's an indication of a problem.
 
hunter24605":2mzph097 said:
Thanks, that's good to hear. The little ridge around the primer strike dimple was concerning. I was told that you should run your fingernail across your primers and if it "snags" that's an indication of a problem.

Not necessarily. The ridge can be explained in many instances by other, non-critical factors.
 
Another way to look at it, since replacing bolt is not a good option. The bolt hole for firing pin is not too large, the firing pin is too skinny. Might search Brownells to see if a new pin is an option.
 
Your firing pin looks to be a bit too short. I would show the brass to Winchester and send the bolt back so they can get it right.
Billy
 
Before I sent it back to Winchester, I ordered a firing pin assembly from Numrich to try to fix the sticking problem without luck, but I kept the assembly..Taking the last two posts into consideration, I swapped out the firing pin with the one I ordered and went to the range a little while ago with the same load as before. The difference is obvious. On the left is today's result with the Numrich replacement pin and the right is with the pin that was in the replacement bolt assembly that Winchester put in it....I haven't taken it back apart to measure them side by side to compare to see if it was too short or too skinny or whatever.

The one on the left is much more uniform than it appears in the pic, the glare makes it look odd. But it's a perfectly round, deep dimple.

Hopefully this settles, once and for all, the issues I've had with this bolt.
 

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hunter24605":2uwuuy4o said:
Before I sent it back to Winchester, I ordered a firing pin assembly from Numrich to try to fix the sticking problem without luck, but I kept the assembly..Taking the last two posts into consideration, I swapped out the firing pin with the one I ordered and went to the range a little while ago with the same load as before. The difference is obvious. On the left is today's result with the Numrich replacement pin and the right is with the pin that was in the replacement bolt assembly that Winchester put in it....I haven't taken it back apart to measure them side by side to compare to see if it was too short or too skinny or whatever.

The one on the left is much more uniform than it appears in the pic, the glare makes it look odd. But it's a perfectly round, deep dimple.

Hopefully this settles, once and for all, the issues I've had with this bolt.
Interesting thread. I'm no expert at reading primers either, but I've never had one that looked like the one on the left. Had many like the one on the right out of many rifles. You mentioned it could be glare in the pic. Could you post a better pic of that primer / cartridge comparison or one like it?
Thank you
Jesse


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hunter24605":2chpx969 said:
Before I sent it back to Winchester, I ordered a firing pin assembly from Numrich to try to fix the sticking problem without luck, but I kept the assembly..Taking the last two posts into consideration, I swapped out the firing pin with the one I ordered and went to the range a little while ago with the same load as before. The difference is obvious. On the left is today's result with the Numrich replacement pin and the right is with the pin that was in the replacement bolt assembly that Winchester put in it....I haven't taken it back apart to measure them side by side to compare to see if it was too short or too skinny or whatever.

The one on the left is much more uniform than it appears in the pic, the glare makes it look odd. But it's a perfectly round, deep dimple.

Hopefully this settles, once and for all, the issues I've had with this bolt.
Interesting thread. I'm no expert at reading primers either, but I've never had one that looked like the one on the left. Had many like the one on the right out of many rifles. You mentioned it could be glare in the pic. Could you post a better pic of that primer / cartridge comparison or one like it?
Thank you
Jesse


Sent from my iPhone using Tapatalk
 
I've already sized and de-primed those cases, so I can't get another pic. but it is the glare making it look odd and misshapen , in real life it is(was) a perfectly dimpled primer.
 
hunter24605":148z8u3p said:
I've already sized and de-primed those cases, so I can't get another pic. but it is the glare making it look odd and misshapen , in real life it is(was) a perfectly dimpled primer.
ok thanks anyways.


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