My Jewell trigger broke! What's going on?

[One-Eyed Jack]

The firing pin block in my Jewell trigger broke in half. I don't know if it broke while firing a round or while loading a new round into the chamber. The result is the firing pin doesn't stay cocked when the bolt is cycled - the firing pin block normally retains the firing pin in the cocked position, ready to release it when the trigger is pulled.

I've sent the trigger to Jewell for repair, but am wondering whether the firing pin is being pulled forward by the bolt closure and putting too much tension on the firing pin block? Could this tension be relieved by shortening the firing pin spring slightly?

The rifle is a KWM using a Surgeon Tactical receiver and there have been about 100 rounds fired with this trigger with no previous signs of a problem.

PS I just read another thread about Jewell triggers and pierced primers. So I checked my spent cases and discovered that one has a pierced primer!! Apparently the solution is to install a bushing in the firing pin hole to reduce gases entering the bolt, pushing the firing pin backward.

 

[djskit]

Call Jewell and see what they say. Surely they will cover it under warranty.

 

[6brshooter]

Three options: bush the bolt and hope it doesn't happen again, different trigger, or reduce loads/ use cci br primers

 

[JRWALLSIII]

Send your Surgeon bolt to Gretan rifles and have him bush the bolt. It's cheap and you'll have it back in a week. He's the best

Jewell will charge you 40.00 more than likely for the repair.

Jewell triggers are great triggers but if you oierce a primer it's broken. You won't pierce another with the bolt bushed.

 

[redneckbmxer24]

Apparently the solution is to install a bushing in the firing pin hole to reduce gases entering the bolt, pushing the firing pin backward.

Jewell's have more problems than that. They gum up very easily (as little as a couple hours from clean trigger to not working) from any sort of dust, whether the wind kicks it up or your muzzle kicks it up. When that happens your rifle no longer goes bang, or goes bang when you touch the bolt knob the eject the live round, neither of which are cool. The latter will get you a DQ from a match. IMO for any kind of field shooting Jewell triggers suck as they're probably the least reliable trigger you can get for a 700.

Rather than spending the money to bush your bolt, get a timney Calvin elite and sell the Jewell. Much more reliable trigger.

 

[One-Eyed Jack]

I've asked Marc Soulie at Spartan to modify an old school Remington trigger to give me a crisp 2-lb pull. I have a couple of GAP rifles with these Remington triggers and they work very well for me. The broken Jewell is on its way to San Marcos, TX and will become a spare in case I have the same problem with another Jewell.

 

[orkan]

I've seen more jewel triggers screwing up in field rifles than any other trigger. Hell, than ALL other triggers combined. They have absolutely no place in a field rifle based on what I've seen. Benchrest/Fclass/etc. That's where they belong.

 

[One-Eyed Jack]

You won't pierce another with the bolt bushed.

How does installing a bushing prevent piercing the primer? I can understand how changing the firing pin tip shape or the firing pin spring constant might do that, but a bushing is just a smaller hole, possibly with less friction for the firing pin. The smaller hole would limit the gas flow into the bolt if the primer is pierced and might save the Jewell.

 

[JRWALLSIII]

With a properly bushed bolt

You will probably blow something else up than pierce a primer

 

[JRWALLSIII]

All triggers fail in tactical match shooting. The debate is never ending on which is best. It's a ford Chevy thing.
That being said some of the very best match shooters in this country still shoot Jewell's

Francis
Morris boys
Preston
Sommers
Long

The list goes on and on

 

[DAVETOOLEY]

How does installing a bushing prevent piercing the primer? I can understand how changing the firing pin tip shape or the firing pin spring constant might do that, but a bushing is just a smaller hole, possibly with less friction for the firing pin. The smaller hole would limit the gas flow into the bolt if the primer is pierced and might save the Jewell.

Pressure is measured in pounds per square inch. Reduce the diameter of the hole and you've reduced the area of the hole. That means less pressure on the primer cup. Reducing the firing pin hole from .080" to .070" reduces the pressure 23%

 

[One-Eyed Jack]

Pressure is measured in pounds per square inch. Reduce the diameter of the hole and you've reduced the area of the hole. That means less pressure on the primer cup. Reducing the firing pin hole from .080" to .070" reduces the pressure 23%

Piercing the primer is a result of mechanical impingement of the firing pin tip on the primer, it has nothing to do with the size of the hole. Once the primer is pierced and ignited, the hot primer gases flow rearward through the puncture and into the firing pin hole, pushing the firing pin backward like a piston toward the trigger group. That's how the firing pin block in my Jewell was broken. It's pretty much like the gas system in an AR. If the size of the hole is reduced, the gas flow into the bolt is restricted and firing pin rearward motion is reduced.

 

[DAVETOOLEY]

Piercing the primer is a result of mechanical impingement of the firing pin tip on the primer, it has nothing to do with the size of the hole. Once the primer is pierced and ignited, the hot primer gases flow rearward through the puncture and into the firing pin hole, pushing the firing pin backward toward the trigger group. That's how the firing pin block in my Jewell was broken. It's pretty much like the gas system in an AR. If the size of the hole is reduced, the gas flow into the bolt is restricted and firing pin rearward motion is reduced.

Wrong about what causes pierced primers. I guess we've been bushing firing pins holes all these years for nothing. Answer me this. Does the firing pin in and of itself cause primer cratering because the next step is pierced primers? So what changed? It wasn't anything to do with the firing pin. Why can just a reduction in powder charge, thus pressure, alleviate cratering and pierced primers ?
There are three main factors that contribute to cratered and pierced primers. In no particular order of importance as they are interdependent. 1. pressure 2. diameter of the firing pin hole. 3. shape of the firing pin tip. A very distant 4th is primer cup thickness and hardness.

You are right about what broke your Jewell. A pierced primer will stop them in their tracks almost 100% of the time.

 

[One-Eyed Jack]

Dave, you're not convincing me about what happened in MY rifle. I have no pressure problems, it's a standard load (and components) for 6XC that I've shot in a few rifles with no other issues or concerns (same as what David Tubb used, but not his heavy 6XC load). I've examined a number of spent cases from this rifle and there are no signs of any problems - especially cratered primers, I know what they look like.

As you stated, firing pin shape and primer construction are among the causes, and I think that's what happened here - based on an examination of my spent cases.

I still don't understand how a bushing or firing pin hole diameter prevents piercing, but I can see how it limits damage if the primer is pierced. Maybe there's more to a bushing than I imagine.

PS I suppose there is the possibility that the case was misloaded. I use a Prometheus II, so it's unlikely that there was a gross overload.

 

[JRWALLSIII]

One eye

While I'm sure you feel it's not a pressure issue...99.99% of the time it is.
And based on some of your statements you have a couple red flags that signal potential pressure issues.

Tooley was spot on about bushing/proper size firing pin hole.

1. You have a barrel with 100 rounds on it....Red Flag....all barrels speed up and usually take up to around 250 rounds to stabilize speed for a particular load. At 100 rounds you could have gained enough velocity to go over pressure. Especially on a hot or rainy day.

2. Your using Tubbs load..... Your mixing powder I see. While lots of folks do it I've always maintained low enough SDs to never need to mix powder. It's dangerous and that could be an issue.

3. My guess is your use to shooting an XC in a .237 barrel. Your new barrel is a .236 and your feeling the effects of pressure in a tight bore. I have burned out 5 XC barrels, I also load on a Gen II. It's common knowledge that a 105 Hybrid with 39.0-39.7 grains of H4350 will usually shoot lights out(In a .237bore) in a .236 you will be over pressure as your barrel speeds up....how do I know???? Well that's what happened to me the first time I pierced a primer with a Surgeon action and jewell trigger combo. I had a spare trigger. 5 rounds later I pierced another primer and broke another trigger.

Sent my bolt to Greg Tannel the very next day. Never another issue.

IMO with the money you have invested you should have your bolt properly bushed to remove a huge variable

Your call.

 

[redneckbmxer24]

Dave is spot on as to why your primer pierced. Pressure and curve is the #1 cause of pierced primers and bushing the hole is the #1 fix aside from a lower pressure load or powder with a longer pressure curve.

 

[One-Eyed Jack]

After only a single primer piercing ever I don't yet believe it's over pressure, but if I get more primer piercings then over pressure becomes more credible as a cause.

Apparently no one can tell me how a smaller primer hole stops primer piercing, I'm one of those guys who needs the details, not just the lore. This is not rocket science, but it should be a science.

What happened to your rifle isn't necessarily what happened to mine and there are a lot of assumptions about my rifle. For example, why does someone believe I'm using mixed powders? Where does the 99.9% statistic come from? If barrels speed up during break in with the same load, that suggests barrel friction is decreasing and there is less peak pressure because the bullet is farther down the barrel.

I shoot identical 6XC rounds in a newish AIAW with a Border barrel and the spent primers and cases look the same as those shot in the KWM. I shoot the same 115DTACs to the same MV as the 6XC (2,970 fps) from the same KMW action with an identical Krieger barrel chambered in 243Win, and the primers look the same as those shot from the 6XC barrel. So there's more anecdotal data about my loads and this same action than I mentioned earlier. No cases or primers have exhibited pressure signs (or sticky bolt lifts) and my 6XC load is relatively mild (in the past couple years, Tubb has launched 6XC 115DTACs at much higher MV to achieve ELR, presumably without a lot of primer piercings). I also had two Tubb rifles and shot the same 6XC rounds. No prior issues at anytime and this load is lights out, that's why I am reticent to change it.

I appreciate your attention to my primer piercing question, but at this point I intend to install the modified Remington trigger when it's ready and head for the range. I need more data to come to any conclusion about primer piercing in my KWM.

 

[JRWALLSIII]

Well ask some of the others top smiths (like tooley) maybe you'll find one with the answer you want to hear.

As far as mixing powder....you sir said that you shoot David Tubbs load. He mixes powder for the XC. Always has. That sir is from the horses mouth.

99.9% statistics....really???? Look at the guys posting on your thread who have vast experience related to this problem. I'm sorry now it's 100% pressure related.

I've spoke my piece. Sir you are more hard headed than I am. That's amazing!!

Good Luck

I'm out

 

[jcallan]

Like Walls I lost 3 Jewell triggers firing a Surgeon 6XC from a 236 bore with 105's that were not over pressure. Once I had Gretan bush the firing pin I have not had one single pierced primer in over 6500 rounds. Get the pin bushed.

 

[DAVETOOLEY]

Apparently no one can tell me how a smaller primer hole stops primer piercing, I'm one of those guys who needs the details, not just the lore. This is not rocket science, but it should be a science.

I did.

 

[cwinner]

Rather than spending the money to bush your bolt, get a timney Calvin elite and sell the Jewell. Much more reliable trigger.

BS on this one.......I saw nearly every Calvin elite trigger fail at a big Match this past April.....they went down fast!! There were lots of trigger failures due to the blowing sand but the new Timneys appeared more sensitive than the rest, a couple Jewell's failed and I'm sure some others as well.....I have a Jewell in my rifle and while it took a lot of maintenance it kept running and has never failed me. (Knock on wood). I do carry a Stock trigger group in my pack in the event I ever have a problem.

 

[KYS]

I would get rid of the jewel and go to a Timney 510 or similar. I run the 517 flat trigger and have them set from the factory at 2.5 lb. Very reliable system!

 

[orkan]

It has always amazed me that people will ask questions, and then argue the answers given by people they ask. If the answer is already known, why ask?

I second the "NO" vote on the calvin. Not good. Stick with the 510.

 

[deadnbrkn84]

LOL Those Timney Calvin Elite's are garbage. I bought 4 of them. Turned around and sold them all. Went out and bought Jewell's. Couldn't be happier.

I like my 510 more then the Calvin's. If you adjust the Calvin to the point where it has no creep then the safety doesn't work. Did this on all 4 of them. Frustrating piece of gear. Buy a 510 and save your money. It's a better trigger.

Apparently no one can tell me how a smaller primer hole stops primer piercing, I'm one of those guys who needs the details, not just the lore. This is not rocket science, but it should be a science.

Believe that's what this was:

"Pressure is measured in pounds per square inch. Reduce the diameter of the hole and you've reduced the area of the hole. That means less pressure on the primer cup. Reducing the firing pin hole from .080" to .070" reduces the pressure 23%"

 

[Bangarang]

Just a quick FYI on a potential new trigger option.

I ordered a couple Rem 700 Tubb Speedlock (Superior Shooting Systems) firing pins and springs yesterday.

The guy taking the order said that Tubb is coming out with a 2-stage trigger for 700s this fall.

I really like the Geiselle 2-stage trigger in my CMP /DCM Highpower A-2 Service Rifle. I will be looking forward to checking out this new Tubb trigger.

 

[One-Eyed Jack]

I had a hard time sleeping last night, the news from Ferguson, MO kept tripping through my head. So I decided to try to sleep by thinking about why a bushing in the firing pin hole would reduce primer piercings. My God, I figured it out!! Here's what I think:

* There is an annular space between the firing pin and the edge of the firing pin hole when the powder load ignites and drives the bullet down the barrel. The mechanical movement of the firing pin is slow compared to the ignition process.

* When the chamber pressure is high enough, cratering rings are imprinted on the primer surface. These rings are formed when the primer shell is pushed back and slightly extruded into this annular space. I used to think the rings were due to impact, but it's really extrusion - pushing metal rearward into the annular space with high pressure. The size of the rings are the size of the annulus.

* At higher chamber pressures, the inside or outside edge of the cratering ring can begin to tear due to shear - the edges of the annular space become a cookie cutter, tearing open the primer and allowing the firing pin to push through.

If this is correct, the absence of cratering rings would indicate that primer piercing is not due to pressure.

Now, how does a firing pin hole bushing fix primer piercings due to high pressure?

* If a proper bushing is installed in the firing pin hole, then the primer surface can no longer be extruded through the annular space because it no longer exists. With a high pressure load, extruded cratering rings are no longer formed and shear forces that tear open the primer are eliminated.

* If the primer is pierced by mechanical impingement of the firing pin, the bushing will prevent gases from entering the bolt and pushing the firing pin rearward, potentially damaging the trigger group.

The last two points show the value of a bushing. While I think my 6XC load is a safe one, I can't be certain that the one round with the pierced primer wasn't misloaded with too much powder -- these rounds were built well over a year ago and I may have been asleep at the switch. Nevertheless, the value of a bushing is to prevent bolt and trigger damage in the event of a misloaded round or a piercing impingement by the firing pin.

Thanks for your persistence, it was probably better for me to figure it out myself.

 

[deadnbrkn84]

There you go.

 

[orkan]

Thanks for your persistence, it was probably better for me to figure it out myself.

It always is... but if you're going to ask a question, don't be so resistant if the question takes you somewhere you're uncomfortable with because you hadn't thought it through.

 

[DAVETOOLEY]

I had a hard time sleeping last night, the news from Ferguson, MO kept tripping through my head. So I decided to try to sleep by thinking about why a bushing in the firing pin hole would reduce primer piercings. My God, I figured it out!! Here's what I think:

* There is an annular space between the firing pin and the edge of the firing pin hole when the powder load ignites and drives the bullet down the barrel. The mechanical movement of the firing pin is slow compared to the ignition process.

* When the chamber pressure is high enough, cratering rings are imprinted on the primer surface. These rings are formed when the primer shell is pushed back and slightly extruded into this annular space. I used to think the rings were due to impact, but it's really extrusion - pushing metal rearward into the annular space with high pressure. The size of the rings are the size of the annulus.

* At higher chamber pressures, the inside or outside edge of the cratering ring can begin to tear due to shear - the edges of the annular space become a cookie cutter, tearing open the primer and allowing the firing pin to push through.

If this is correct, the absence of cratering rings would indicate that primer piercing is not due to pressure.

Now, how does a firing pin hole bushing fix primer piercings due to high pressure?

* If a proper bushing is installed in the firing pin hole, then the primer surface can no longer be extruded through the annular space because it no longer exists. With a high pressure load, extruded cratering rings are no longer formed and shear forces that tear open the primer are eliminated.

* If the primer is pierced by mechanical impingement of the firing pin, the bushing will prevent gases from entering the bolt and pushing the firing pin rearward, potentially damaging the trigger group.

The last two points show the value of a bushing. While I think my 6XC load is a safe one, I can't be certain that the one round with the pierced primer wasn't misloaded with too much powder -- these rounds were built well over a year ago and I may have been asleep at the switch. Nevertheless, the value of a bushing is to prevent bolt and trigger damage in the event of a misloaded round or a piercing impingement by the firing pin.

Thanks for your persistence, it was probably better for me to figure it out myself.

I thought you had it right up until you said the bushing would prevent gas from entering the firing pin hole. A pierced primer guides/directs gas directly into the firing pin hole. The reduced diameter reduces the shear load on the primer cup. The firing pin actually supports and reduces the flow of the cup. That's why the shape is important.

I'm done

 

[orkan]

I thought you had it right up until you said the bushing would prevent gas from entering the firing pin hole. A pierced primer guides/directs gas directly into the firing pin hole. The reduced diameter reduces the shear load on the primer cup. The firing pin actually supports and reduces the flow of the cup. That's why the shape is important.

I'm done

... as you should be. The right answer has been given many times here, twice by you. (or three?) lol

 

[Bill Larson]

Dave, you're not convincing me about what happened in MY rifle. I have no pressure problems, it's a standard load (and components) for 6XC that I've shot in a few rifles with no other issues or concerns (same as what David Tubb used, but not his heavy 6XC load). I've examined a number of spent cases from this rifle and there are no signs of any problems - especially cratered primers, I know what they look like.

As you stated, firing pin shape and primer construction are among the causes, and I think that's what happened here - based on an examination of my spent cases.

I still don't understand how a bushing or firing pin hole diameter prevents piercing, but I can see how it limits damage if the primer is pierced. Maybe there's more to a bushing than I imagine.

PS I suppose there is the possibility that the case was misloaded. I use a Prometheus II, so it's unlikely that there was a gross overload.

you asked for help....with pierced primers....... BUT......you`ve got more than one problem......You don`t take the advice of people who know more about the subject than you.....to the point of arguing with gunsmiths that have been curing this problem for years.....