Pressure problem

[CHA-LEE]

Rifle Primers are pretty much required in 9 Major loads due to the insane pressures they are exposed to.

 

If you get light strikes with an extended firing pin then you need a heavier hammer spring.

[xjwalt666]

Do you have any other powders you can try?  WAC is the powder I have had the least luck with, followed by HS6.   I like Silhouette, 3n38 and AA7. 

I have silhouette and hs6. Like I posted above, 8.0 gr of hs6 leaves a normal strike in the primer. I'm really starting to wonder if this is a bad batch of primers also. The hs6 loads are from a couple boxes of primers before the WAC loads. Bought a few months apart. I need to chrono the hs6 loads to see where they are at for pf and go from there I think.

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[theWacoKid]

I concede many people have success with Autocomp but I always suggest avoiding it. 

 

Springs and such have nothing to do with your problem. It is your load with Autocomp and these primers. Yes, bad batches of primers happen. Change something with your load. 

[MikeBurgess]

Take a close look at the tip of your firing pin.
I had a issue recently where the tip fractured off my pin leaving a flat ish face to the pin with just rounded corners. It was hard to see with out some magnification for my old eyes. When I tore the gun down there were small disks of primer brass everywhere.
Looking at the posted picture the primer does not look over pressured



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[xjwalt666]

Take a close look at the tip of your firing pin.
I had a issue recently where the tip fractured off my pin leaving a flat ish face to the pin with just rounded corners. It was hard to see with out some magnification for my old eyes. When I tore the gun down there were small disks of primer brass everywhere.
Looking at the posted picture the primer does not look over pressured



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Firing pin is fine. Checked it first under microscope at work.

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[schaet]

Going by the pictures there are two things that stick out: 

1. The primer doesn't look like there's a pressure problem because looking at the shape of it still in the pocket; it's not too flattened out. IE. there is a still good contour on the edges. It does look a bit flat on the overall surface, but it doesn't look excessive.

2. Your firing pin looks to be protruding a bit from the breach face. This is where I would look. You may have a weak or incorrect firing pin spring resulting in the firing pin going to deep into the primer. 

The next question I expect would be why is this happening only with major loads, but the minors don't do it? I suspect that the firing pin in going too deep, but not deep enough to pierce the primer, however it maybe weakening it enough that when the elevated pressure from the major load hits it, it blows out that piece. 

 

Things that come into play here: 

1. Main spring > 17# should be fine for a standard length firing pin, maybe too much for your extended one with a possibly weakened firing pin spring

2. Possibly weakened firing pin spring > hammer is throwing the firing pin too deep

3. Wrong components > really don't think this is the case, but gotta throw it out there just incase  

4. Firing pin OAL and how far it extrudes from the FPS (off the top of my head I can't remember the spec for this)

5. The firing pin stop > again I really don't think this may be it, but it does come into play in the overall system. Could be worn etc. 

 

Things to try: 

1. Replace the firing pin spring. Standard and possibly a stronger one

2. Replace the extended firing pin with a standard one

3. Lighter main spring

 

Just some thoughts .. I'm really interested in the fix. Keep us posted! 

[DirtDiver]

Change primers to SRP Federal, make sure that the primmer is seated fully, this means with a slight recess, when reloaded.

[pskys2]

Same issues when we started upping pressures on 38 supers to 180 pf's.  

Being a 9 mm slide, the fp will be small.  You can try a Titanium FP, they seemed to help a little.

Real culprit is the pressure vs the primer.  Small Pistol, even magnum, Primers would do shear off metal into the firing pin hole. Leading to FTF's.  The flatness of the primer in the pocket won't tell you anything.  Remember you are working at +P++ or more pressures.

Small Rifle Primers are the 1st step, changing powder would be the next.  Back in the day it was Winchester Small Rifle Primers that gave the best results.

If the action is unlocking too quickly as in too light of a recoil spring or the barrel was not fit correctly it can also lead to this issue.  But if the gun is accurate that is a doubtful issue.  And it sounds as if your set up is good as far as mainspring and recoil spring weights go.

Edited August 23, 2018 by pskys2

[jim vaughan]

Find out how much lead is in your barrel (not lead as in bullet material).

Has the initial rifling been removed for say 4-5mm?

This is standard practice to reduce pressure signs in open handguns.

[Maximis228]

I load 7.4 of Wac under a 124 PD. Going out of a 5.5 inch SV hybrid barrel .Hits 177-180 PF depending on the day and chrono.

 

CCI 500 primers. M2I extended firing pin.

 

Never seen pressure issues when shot out of my guns.

Edited August 23, 2018 by Maximis228

[xjwalt666]

Going by the pictures there are two things that stick out: 
1. The primer doesn't look like there's a pressure problem because looking at the shape of it still in the pocket; it's not too flattened out. IE. there is a still good contour on the edges. It does look a bit flat on the overall surface, but it doesn't look excessive.
2. Your firing pin looks to be protruding a bit from the breach face. This is where I would look. You may have a weak or incorrect firing pin spring resulting in the firing pin going to deep into the primer. 
The next question I expect would be why is this happening only with major loads, but the minors don't do it? I suspect that the firing pin in going too deep, but not deep enough to pierce the primer, however it maybe weakening it enough that when the elevated pressure from the major load hits it, it blows out that piece. 
 
Things that come into play here: 
1. Main spring > 17# should be fine for a standard length firing pin, maybe too much for your extended one with a possibly weakened firing pin spring
2. Possibly weakened firing pin spring > hammer is throwing the firing pin too deep
3. Wrong components > really don't think this is the case, but gotta throw it out there just incase  
4. Firing pin OAL and how far it extrudes from the FPS (off the top of my head I can't remember the spec for this)
5. The firing pin stop > again I really don't think this may be it, but it does come into play in the overall system. Could be worn etc. 
 
Things to try: 
1. Replace the firing pin spring. Standard and possibly a stronger one
2. Replace the extended firing pin with a standard one
3. Lighter main spring
 
Just some thoughts .. I'm really interested in the fix. Keep us posted! 

Firing pin spring is an extra power wolf spring. The whole setup has between 2500-3000 rounds thru it total. I'm going to try a standard firing pin this weekend hopefully. But the strangest part is it only happens with this load. I ran 8.0 of hs6 at same length same head and same primers with zero issues.

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[xjwalt666]

Change primers to SRP Federal, make sure that the primmer is seated fully, this means with a slight recess, when reloaded.

Going to try this as well. Going to pick some up after work today.

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[xjwalt666]

Same issues when we started upping pressures on 38 supers to 180 pf's.  
Being a 9 mm slide, the fp will be small.  You can try a Titanium FP, they seemed to help a little.
Real culprit is the pressure vs the primer.  Small Pistol, even magnum, Primers would do shear off metal into the firing pin hole. Leading to FTF's.  The flatness of the primer in the pocket won't tell you anything.  Remember you are working at +P++ or more pressures.
Small Rifle Primers are the 1st step, changing powder would be the next.  Back in the day it was Winchester Small Rifle Primers that gave the best results.
If the action is unlocking too quickly as in too light of a recoil spring or the barrel was not fit correctly it can also lead to this issue.  But if the gun is accurate that is a doubtful issue.  And it sounds as if your set up is good as far as mainspring and recoil spring weights go.

Going to try small rifle primers today. Maybe that will be the key.

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[SilverBolt]

Make one change at a time and test.  

[191138sc]

7 minutes ago, SilverBolt said:

Make one change at a time and test

Agree. You have been given many good suggestions to try and fix this issue. Please do ONE at a time. If you change two things then you never know which one fixed the problem. Always go with the cheapest and easiest fix first. Good luck and let us know what fixed your issue.

[DirtDiver]

Please look closely at the primmer dept.....each primer is seated completely in the primmer pocket so when the firing pin hits the primmer it does not finish seating the primer.

 

 

Edited August 23, 2018 by DirtDiver

[DirtDiver]

Please look closely at the primmer dept.....each primer is seated completely in the primmer pocket so when the firing pin hits the primmer it does not finish seating the primer.

[TONY BARONE]

Head space could be an issue. I had the same problem with an extended firing pin tried std. pin same results switched to a Sti Ti pin no longer any primer holes.

[xjwalt666]

Make one change at a time and test.  

I will. I changed powder first. Same issue. Then changed to winchester spp because I had some and still same issue today. Next i will change the firing pin spring since i have a spare. And i also grabbed some small rifle primers today to try.

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[xjwalt666]

Please look closely at the primmer dept.....each primer is seated completely in the primmer pocket so when the firing pin hits the primmer it does not finish seating the primer.

I go thru and check every round to make sure fully seated. And I take the time when loading to make sure I make full stroke down and up and push all the way for the primer seating.

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[xjwalt666]

Yesterday I had tried 7.5 of hs6 with cci spp abd had the same problem. Last night I switched to winchester spp abd again today same problem and average of 1330fps for 164pf. Tried with a 10lb and an 11lb recoil spring. Same issue with both. Could the spring be causing it to lock up too long and that's why its shaving the primer?

 

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[superdude]

11 minutes ago, xjwalt666 said:

Could the spring be causing it to lock up too long and that's why its shaving the primer?

 

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The primer material is being sheared off because the primer material is flowing into the firing pin hole because the pressure is so high.  

[xjwalt666]

 
The primer material is being sheared off because the primer material is flowing into the firing pin hole because the pressure is so high.  

I understand that. But what I dont understand is I'm below what others are running in similar setups with higher power factor and not having a high pressure issue.

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[superdude]

Chamber dimensions, length of leade, etc. can raise or lower pressure.  It would be wonderful to be able to assess WHY you're having a pressure issue, but that might get complicated and require special instruments and/or require you to ream the chamber.

 

The best we can offer is ways to prevent primer flow, be that changes in powder, charge weight, primer, firing pin geometry, etc.  

 

A rifle primer might solve the primer flow issue if different powders produce the same result.  One powder that tends to run low pressure in 9 Major is 3N38, since it can produce high velocity in the 9mm at normal operating pressure.  But I'd start with a rifle primer and see what that does. 

 

The recoil spring does not really have a role here. It will change timing a little, but it does not cause primer flow. Your problem is primer flow. Address that.

[orangeman711]

As others have stated I would lower the powder volume and go to a small rifle primer. I run 6.9 grs. of WAC and chrono 170.5-171.5. good luck.