Pierced a primer, now it won't shoot. What to check?

[dcali]

And here's a close up of the primer next to a normal one. The normal looking one may have been from a hotter or lighter load. I can't recall. But it would have been similar.

 

[gme]

if it were mine I'd probably look at ignition, a customer had a similar problem (primer did blank), turned out the tip of the firing pin became slightly bent and was dragging on the side of the hole (it was visible), replaced the firing pin and the issue went away

 

[jimmymac]

Looks like there is a little raised ridge inside the crater on the “good” primer. Are they all that way? I don’t know enough to say what that means, but it sure caught my eye. Hope you get it worked out..

 

[dcali]

Looks like there is a little raised ridge inside the crater on the “good” primer. Are they all that way? I don’t know enough to say what that means, but it sure caught my eye. Hope you get it worked out..

That's just a reflection. It feels smooth when I drag a pin across it.

 

[dcali]

if it were mine I'd probably look at ignition, a customer had a similar problem (primer did blank), turned out the tip of the firing pin became slightly bent and was dragging on the side of the hole (it was visible), replaced the firing pin and the issue went away

This is the only thing I can see that could be wrong. There is a slight bend to the pin, but it's about .005". You can see some marks on one side of the pin where it drags, but it's very minor - you almost need a magnifier to see it. Jim that a little rubbing is normal, and .005" is nothing to be concerned about. At this point, if a new trigger and cleaning it up doesn't help, that's the only clue I've got.

 

[geo.ulrich]

It's hard to get a picture of it, but it looks like the primer was hit, cratered a tiny bit, adn then was pushed back flat, but stopped when it got flat - not going all the way to shear off the disc. The outer, slightly raised circle is from the firing pin hole. The ding in the middle looks like it could be from the pin? But it's hard to say. It looks weird. No primers have been actually pierced in this rifle - so it's not like a disc got stuck in there.

Bolt face and pin tip pictures attached.

bolt face looks alittle strange like there is a slight burr at edge of hole and a recess possibly where primer would seat, but it could be reflection in picture. the "pop" is strange. time to tear everything apart check all scope screws look for crack in scope rings remove scope and shake it see if you hear anything loose inside also I would stick another scope on just for peace of mind.

 

[geo.ulrich]

comparing the two primers it looks like a soft hit with the messed up one. dig into striker assem. check pin fall length not protrusion should be around .240

 

[carlsbad]

This is the only thing I can see that could be wrong. There is a slight bend to the pin, but it's about .005". You can see some marks on one side of the pin where it drags, but it's very minor - you almost need a magnifier to see it. Jim that a little rubbing is normal, and .005" is nothing to be concerned about. At this point, if a new trigger and cleaning it up doesn't help, that's the only clue I've got.

Damon,
I see marks like that and runout along the lines of .005 frequently on bolts/pins sent to me for bushing. It isn't unusual but it isn't a good thing. Of course once I turn the pin, there is no runout.

The lack of accuracy you are describing would be invisible to many (1/4" groups open up to 3/4" groups).

poor or inconsistent ignition is certainly a contributor to loss of accuracy. I would order a new firing pin, they aren't expensive. IN the mean time, I'd put this one in the collet and push it just behind the .070" portion, on the taper, with the tool post to eliminate the runout. (straighten it). See if that helps. Worst you can do is ruin a firing pin.

The other thing I would do is use long swabs or other tools to cleand the deep inside surfaces of the bolt. if gas did escape it could have blown dirt or debris around and causes some interference with the seating surface of the firing pin.

--Jerry

 

[coldboreshot]

Damon,
I see marks like that and runout along the lines of .005 frequently on bolts/pins sent to me for bushing. It isn't unusual but it isn't a good thing. Of course once I turn the pin, there is no runout.

The lack of accuracy you are describing would be invisible to many (1/4" groups open up to 3/4" groups).

poor or inconsistent ignition is certainly a contributor to loss of accuracy. I would order a new firing pin, they aren't expensive. IN the mean time, I'd put this one in the collet and push it just behind the .070" portion, on the taper, with the tool post to eliminate the runout. (straighten it). See if that helps. Worst you can do is ruin a firing pin.

The other thing I would do is use long swabs or other tools to cleand the deep inside surfaces of the bolt. if gas did escape it could have blown dirt or debris around and causes some interference with the seating surface of the firing pin.

--Jerry

I am suspecting this as well. The ping your heard was most likely the firing pin itself making contact, other than the primer.

 

[geo.ulrich]

so all was good before this one cartridge and all the sudden firing pin became bent and rifle stopped shooting. causing 1 m.o.a. .005 is not gonna do this. its not great but its a lot better than a bunch of others.

 

[Crosshair1]

I think the "flat" primer is showing excessive pressure, the case head looks like it has a significant mark from the ejector which is not that easily done to palma brass.
It looks as if the firing pin is pushed back, were this a looser fitting pin it would probably result in a pierced primer.
I'd be looking at the neck area, say a case with excessive neck length causing a crimp, from the look of the primer it was hard against the bolt face when fired as it has retained more of an edge radius that the "good" primer.

 

[dcali]

Still something of a mystery. I pulled the firing pin assembly apart, and nothing appears wrong anywhere. It's possible something is wrong with the pin that I'm not able to measure properly. I guess I'll just clean it all back up and try it again. Any reason to question the spring? It looks normal.

I've got a new trigger, pin, and spring on order. Hopefully that will fix it if cleaning it and putting it all back together won't.

 

[carlsbad]

At this point I would be thinking the problem probably isn't in my bolt. I'd look at my reloading. did something change that caused the high pressure and is now causing the loss of accuracy?

Carbon ring in the neck?

 

[dcali]

At this point I would be thinking the problem probably isn't in my bolt. I'd look at my reloading. did something change that caused the high pressure and is now causing the loss of accuracy?

Carbon ring in the neck?

It's not the loads. The offending shot threw the bullet WAY to the right. I didn't measure, but at least 5" at 100. The very next, and all subsequent shots had a different POI. Accuracy was at BEST .75" from this rifle afterwards, with one two-shot group over 2". Previously, I was able to shoot 3 shot groups fairly regularly in the .2s, and .4s were easy. The worst groups that day before the bad shot were about 0.5 MOA. Something happened. I'm just not sure what. It may be that the tube gun chassis shifted? I don't know. It's not glued in.

There is a little carbon in the neck, but not enough to wreck anything. This barrel only has about 700 rounds on it. The case was 2.009" after firing. SAAAMI max is 2.015".

I'm starting to think that it will be fine when I put it all back together.

 

[Link]

Can you see light through the center of the primer? Just wondering.
Don

 

[dcali]

Can you see light through the center of the primer? Just wondering.
Don

No - it's not pierced at all. You can see the indent from the anvil on the inside - that *may* be responsible for the inner ring you can see on the outside of the primer.

 

[geo.ulrich]

It's not the loads. The offending shot threw the bullet WAY to the right. I didn't measure, but at least 5" at 100. The very next, and all subsequent shots had a different POI. Accuracy was at BEST .75" from this rifle afterwards, with one two-shot group over 2". Previously, I was able to shoot 3 shot groups fairly regularly in the .2s, and .4s were easy. The worst groups that day before the bad shot were about 0.5 MOA. Something happened. I'm just not sure what. It may be that the tube gun chassis shifted? I don't know. It's not glued in.

There is a little carbon in the neck, but not enough to wreck anything. This barrel only has about 700 rounds on it. The case was 2.009" after firing. SAAAMI max is 2.015

you might want to look into case length again and compare to reamer did gunsmith give you a chamber gage to check clearance to end of chamber, I run tight 005 clearance and have been bite by this but this is checked with a gage

 

[dcali]

you might want to look into case length again and compare to reamer did gunsmith give you a chamber gage to check clearance to end of chamber, I run tight 005 clearance and have been bite by this but this is checked with a gage

I have a stub - I'll check. The reamer's freebore was .010" too long, so it's not out of the question that it was jacked up.

Edit: Looks good. Plenty of clearance.

 

[Alex Wheeler]

When you have weak enough ignition or enough drag you can hear the firing pin drop. Compress the spring as much as you can and inspect the inside of the shroud. The older Borden shrouds were fit tightly in this area and debris or a protruding cocking piece pin can cause drag. Weak hits can cause poi shift.

 

[skiutah02]

It may be that the tube gun chassis shifted? I don't know. It's not glued in.

Tube gun you say....

Probably a wild hare, but I know some fellows that noticed in the Eliseo that if the following plastic set screws were not snug, the gun flexed and the shots were all over. I've marked the offenders with arrows for you. I've never had an issue, but I know two that drove themselves crazy chasing down an issue that turned into this solution. I'm voting for a "dirt in the wrong place" or "broken trigger/spring/firing pin" myself, but would feel bad if I didn't share this one.
Drew