Failure to fire - Light Primer Strikes?

[Florida Wally]

I am having failures to fire with my 308. Kelbly F-class Panda action with a Jewell BR trigger with about 1,000 rounds on it. I am getting 2 or 3 out of 50 misfires. I would get misfires periodically during the first 900 rounds, but now they are regular occurrences. I am using BR4’s and have tried CCI 450’s and both Lapua Palma and Alpha OCD brass. I am bumping fire formed brass 0.002” when I resize so I don’t think the issue is too much headspace. I seat the primers with the anvil touching the bottom of the cup +0.004” to 0.005”. In the photo below, the left is a misfire with no firing pin mark at all, the middle is a misfire with what looks to be a light strike and the right is a primer that did fire. Using my inexpensive calipers, I measured the pinfall to be about 0.250” (cocking piece to shroud cocked is 0.035” and shroud to cocking piece uncocked is 0.215”). I’ve also measured the firing pin protrusion to be 0.048”.

Should I try to change the firing pin spring, send the action to Kelbly’s, take the rifle to a gunsmith, or try anything else? I’m somewhat new to custom rifles and am not sure what to do.

 

[LVLAaron]

The primer on the far right didn't ignite?

 

[Florida Wally]

The primer on the far right didn't ignite?

That round fired. I included it for reference.

 

[Sniperhandle]

I am having failures to fire with my 308. Kelbly F-class Panda action with a Jewell BR trigger with about 1,000 rounds on it. I am getting 2 or 3 out of 50 misfires. I would get misfires periodically during the first 900 rounds, but now they are regular occurrences. I am using BR4’s and have tried CCI 450’s and both Lapua Palma and Alpha OCD brass. I am bumping fire formed brass 0.002” when I resize so I don’t think the issue is too much headspace. I seat the primers with the anvil touching the bottom of the cup +0.004” to 0.005”. In the photo below, the left is a misfire with no firing pin mark at all, the middle is a misfire with what looks to be a light strike and the right is a primer that did fire. Using my inexpensive calipers, I measured the pinfall to be about 0.250” (cocking piece to shroud cocked is 0.035” and shroud to cocking piece uncocked is 0.215”). I’ve also measured the firing pin protrusion to be 0.048”.

Should I try to change the firing pin spring, send the action to Kelbly’s, take the rifle to a gunsmith, or try anything else? I’m somewhat new to custom rifles and am not sure what to do.If you have had any pierced primers in the past, Your bolt may have some [ inside causing failure to fire. Loose headsspace can also cause it. I would disassemble the bolt and clean it out first.

If you have had pierced primers in the past, There may be some primer blanks inside causing a failure to fire, I would disassemble the bolt and clean it out good to see if that is what is causing it. Loose headspace can also cause failure to fire, As the firing pin pushes the case forward losing it's length of travel and inertia.

 

[Florida Wally]

If you have had pierced primers in the past, There may be some primer blanks inside causing a failure to fire, I would disassemble the bolt and clean it out good to see if that is what is causing it. Loose headspace can also cause failure to fire, As the firing pin pushes the case forward losing it's length of travel and inertia.

Thanks for pointing this out. I should have mentioned in my OP that I just dissembled the bolt and cleaned it. It wasn’t too dirty since I clean it often. Before the misfires today, I removed the firing pin, cleaned the inside of the bolt with a brush, patches and q-tips using isopropyl alcohol. I also looked it over with a Teslong before reassembling.

 

[gunsandgunsmithing]

If you have had pierced primers in the past, There may be some primer blanks inside causing a failure to fire, I would disassemble the bolt and clean it out good to see if that is what is causing it. Loose headspace can also cause failure to fire, As the firing pin pushes the case forward losing it's length of travel and inertia.

Yes, the one with no hit tells the story. There pretty much has got to be something inside the bolt that kept the fp from coming all the way forward. I'd change the spring while you're there but clean everything really well, re-lube with a very light coat of very light viscosity oil and put it back together. A little grease on the shroud threads and I bet it fixes it. Something kept the fp from getting to the primer. That's the easy and cheap place to start looking. Good idea to take the trigger out and give it a really good clean and lube with lighter fluid too. Gets a little more in depth from there but not many things that will do that.

 

[gunsandgunsmithing]

Thanks for pointing this out. I should have mentioned in my OP that I just dissembled the bolt and cleaned it. It wasn’t too dirty since I clean it often. Before the misfires today, I removed the firing pin, cleaned the inside of the bolt with a brush, patches and q-tips using isopropyl alcohol. I also looked it over with a Teslong before reassembling.

Then figure out what kept the pin from going all the way forward. I'd still bet something was in the bolt. At least most likely. It could've fallen out when you took it apart. A likely culprit is a tiny disc from a pierced primer.

 

[Florida Wally]

Then figure out what kept the pin from going all the way forward. I'd still bet something was in the bolt. At least most likely. It could've fallen out when you took it apart. A likely culprit is a tiny disc from a pierced primer.

I cleaned it really well before I had the misfires today. I’m certain nothing is in the bolt.

 

[gunsandgunsmithing]

I cleaned it really well before I had the misfires today. I’m certain nothing is in the bolt.

Do we agree that something stopped the pin from reaching the primer? I mean, it shouldn't be hard to figure it out unless it was in the bolt and fell out and you just didn't see it. I think that's very possible unless you were doing this over a clean white or similar surface or similar. Just not much to this aspect of a gun. It has to be mechanical. Know what I mean Vern.Lol!

 

[NorCalMikie]

Brass problem!! (headspace) Too short, gets pushed forward in the chamber and you get FTF! See if your fired brass will "rechamber with no resistance". If so, neck size and reload. Start there!!

 

[gunsandgunsmithing]

Brass problem!! (headspace) Too short, gets pushed forward in the chamber and you get FTF! See if your fired brass will "rechamber with no resistance". If so, neck size and reload. Start there!!

Yessir. He said he was bumping .002...fwiw. Even still, the first has no hit at all showing, which would seem to indicate at least fp protrusion amount, I think he said .048 iirc. A little on the short side but should not be problematic unless other contributing factors, imo.

 

[Florida Wally]

Do we agree that something stopped the pin from reaching the primer? I mean, it shouldn't be hard to figure it out unless it was in the bolt and fell out and you just didn't see it. I think that's very possible unless you were doing this over a clean white or similar surface or similar. Just not much to this aspect of a gun. It has to be mechanical. Know what I mean Vern.Lol!

I cleaned the bolt really well last night and looked it over with a Teslong borescope after yesterdays misfires. I took the clean rifle to the range and shot loads with a different lot of primers. After four shots, the fifth fifth misfired.

I did compress the spring pretty far with the spring tool yesterday. I was checking for burrs in the cross pin. Could that have aggravated the misfires? Also, I did feel a little burr that I lightly polished where the firing pin cross pin is.

 

[gunsandgunsmithing]

I cleaned the bolt really well last night and looked it over with a Teslong borescope after yesterdays misfires. I took the clean rifle to the range and shot loads with a different lot of primers. After four shots, the fifth fifth misfired.

I did compress the spring pretty far with the spring tool yesterday. I was checking for burrs in the cross pin. Could that have aggravated the misfires? Also, I did feel a little burr that I lightly polished where the firing pin cross pin is.

Possibly but .048"? What are you lubing it with? It's possible in cold weather it's "hydraulicing", stopping or greatly slowing the pin down. Sounds like you're looking in the right places and just haven't found it yet.

 

[NorCalMikie]

Yessir. He said he was bumping .002...fwiw.

I saw that BUT, he's doing it, and not me so, only way to prove what he did is good or bad is to bypass the bump and see what happens.
I could be all wet but, the only way to find out "for sure" is to do it!!
Sometimes we can't see the forest for the trees.

 

[gunsandgunsmithing]

I saw that BUT, he's doing it, and not me so, only way to prove what he did is good or bad is to bypass the bump and see what happens.
I could be all wet but, the only way to find out "for sure" is to do it!!
Sometimes we can't see the forest for the trees.

Yes, I agree. It's hard on the interweb to know what's on the other end but him checking for burrs on the cocking piece sounds like he's probably sharp enough to figure this out. Myself, just trying to help, like you. Sometimes it's something simple if it's in your hand but impossible on the internet. I'm with ya.

 

[Florida Wally]

Possibly but .048"? What are you lubing it with? It's possible in cold weather it's "hydraulicing", stopping or greatly slowing the pin down. Sounds like you're looking in the right places and just haven't found it yet.

I’m not lubing anything on the inside of the bolt. Maybe that’s the problem. I only put Kelbly’s action grease on the last few threads of the shroud and on the lugs. It is colder than usual, but it was only 41 degrees today.

 

[gunsandgunsmithing]

KISS it before jumping to the hardest and rarest of all solutions. Lol! There's usually a simple solution that gets overlooked.

 

[gunsandgunsmithing]

I’m not lubing anything on the inside of the bolt. Maybe that’s the problem. I only put Kelbly’s action grease on the last few threads of the shroud and on the lugs. It is colder than usual, but it was only 41 degrees today.

A really thin coat of thin oil is usually all ya need. Sounds like you're on the right track to me. I wish I could tell ya more but I think you're sharp enough and you're going through the right steps. Just double check the simple stuff.

 

[gunsandgunsmithing]

It could be in the trigger. Does it sound and feel right if dry fired? Some pretty serious drag somewhere.

 

[Florida Wally]

I saw that BUT, he's doing it, and not me so, only way to prove what he did is good or bad is to bypass the bump and see what happens.
I could be all wet but, the only way to find out "for sure" is to do it!!
Sometimes we can't see the forest for the trees.

I suspected bump first. With the firing pin out, a fired brass will fit, but it needs some pressure on the bolt handle. I bump from there 0.002”. As another check, I checked the chamber with a go and nogo gauges and chamber is correct. I then measured the shoulder with an RCBS micrometer headspace gauge and the sized cases are 0.002” shorter than the go gauge.