I’ve never had an issue with a 20# hammer spring. Is yours well-used by chance?

quote:

Originally posted by Chris Orndorff:
I’ve never had an issue with a 20# hammer spring. Is yours well-used by chance?

It was a brand new wolf spring that I ordered specifically to replace the factory spring (which was well used) because I was getting the light strikes. I also ordered a 24lb, 26lb, and 28lb at the same time...I just mistakenly thought that the 20lb was the factory weight so I started with that. It's possible that the mainspring isn't the problem at all, but I'm going to give it a try this weekend and find out. If it still doesn't work I can go up to 28lb and rule it out altogether.

The gun in question was a surplus import, so it's had a pretty rough life all around.

Those heavy springs might mask the root issue. Can you check headspace?

quote:

Originally posted by Chris Orndorff:
Those heavy springs might mask the root issue. Can you check headspace?

I don't have headspace gauges if that's what you're asking. Is there another method that I could use to do that?

Not that I know of. Have access to another barrel?

This is actually the second (used) barrel. The first one was worn out and had excess play in it's lockup with the takedown lever. You may have nailed the problem here, although the current barrel appears to lock up tight.

Here's the original thread on this gun, that ended with me thinking I'd resolved the problem by replacing the barrel.
https://sigforum.com/eve/forum...935/m/4330024305/p/1

With a removeable barrel like that I always thought we checked headspace just by dropping a cartridge in the chamber and checking to see that the case base was just slightly below flush with the barrel hood extension that contacts the breech face.

This is about what I usually expect.





The case head should obviously not sit above the barrel hood extension because that could prevent proper barrel lockup. This is a gross exaggeration and due to an oversized case, but if the barrel headspace were too short for a standard load, the case head would sit somewhat similarly, but probably not as far.





If the chamber headspace is excessive, the cartridge would sit in too far and that would reduce the firing pin impact. The same thing would also occur if the cartridge cases were trimmed too short.

At least all that’s my understanding of the issue.

Yes, I do that regularly when checking reloads with the "plunk" test, and it has always worked fine for "rough headspacing". Mine looks like the top picture, but I have no way of measuring the exact offset from the top of the hood to the case head (I guess I could give it a shot with my calipers, but it won't be incredibly precise), nor do I have any idea what the proper spec is supposed to be.

Great pics and description John, but my eyes aren’t calibrated to .010” . So it might look good, but could still be off enough to affect ignition.

Obviously something’s wrong here, but I don’t think it’s the hammer spring. If the hammer is not square in the frame (evidenced by unusual wear on one side of the hammer), the hammer speed is impeded. A damaged firing pin won’t move properly in its channel. Just guessing here, but this one’s a puzzle.

92, thanks for keeping us updated!

I measured the offset between the back of the case head and the top of the barrel hood...it's between 0.011" and 0.012", best as I can tell by hand with a set of dial calipers.

I'll check the hammer for wear. The firing pin is moving freely, doesn't bind, and protrudes cleanly through the breech face. The gun fires as intended probably 95-98% of the time.

Thank you guys for the help and for giving me ideas!

ETA: I just took the same measurements on my other 9mm P-Series Sigs. My P6 barrel shows the exact same measurement as the P228 (0.011-0.012"). That gun does not have light strikes, but has the typical heavy hammer spring of the type. My P229-1 SAS has a much tighter tolerance of 0.001"....also no light strikes there. Not sure why the different tolerances, though.

This message has been edited. Last edited by: 92fstech,

I detail stripped the frame again this morning (minus the mag catch because I figured that has no relevance). The hammer has a few scuff marks on it, but nothing significant. There was a small burr on the frame (sorry for the crappy out of focus pic...couldn't get my phone to cooperate) that I think was actually down below the hammer stop, but I hit it with some sand paper anyway and smoothed it flush. I also lightly stoned the sides of the hammer, but honestly couldn't feel any burrs or anomalies before I did that.

I replaced the hammer rebound spring while I was in there because I had some new ones on hand, but the original one was not broken. I'm hoping to get it out to the range again today with the 24lb spring, so we'll see how that goes.

Took it to the range this morning and ran the postal match drill. First 18 rounds went off no problem (except for my crappy shooting). I though maybe it was fixed.

Second run I had a light strike about 5 rounds in. Then another at 7 or 8. Then I moved over to the plate rack and had two more. They happen in DA and SA. Usually the rounds will fire on a second pull. I saved the first two light-strike rounds and took photos. They're the two at the top.

I realzied I actually have a 9mm case gauge that I've never used (I typically just plunk test in the barrel). Both cases are slightly proud in the case gauge (lower left)...in contrast to a factory HST, which is just sub-flush (lower right). All three rounds sit about the same in the barrel, though, with my (admittedly questionable) caliper technique measuring between 0.10-0.13" off the top of the barrel hood. So headspace should be similar.



Cearly the ammo doesn't gauge quite perfectly, but I've had zero issues with it in any of my other guns. The primer strikes also don't appear to be perfectly centered, but I've compared them to brass from my P229 in the past, and it's very similar.

Can you think of any reason I couldn't put my P229-1 Upper on the P228 frame and shoot it that way? It seems to fit. That would potentially pinpoint whether the issue I'm dealing with is related to the upper or the lower.

I would be concerned about the off-center firing pin strikes.
Although I’ve never seen any definitive discussion of why they occur, I assume that it has to do with how the barrel locks into the slide and therefore where the primer is positioned with respect to the firing pin. If the barrel to slide lockup positions the barrel a little high, then the strikes would be closer to the bottom of the primer, and of course they would be nearer the top of the primer if the barrel was a little low.

I’ve lost track of everything you’ve tried, but if it were me, I’d test to see what might be the cause of the off-center strikes: load a round or even primed case in the chamber with its orientation clearly marked, and then after it’s fired see where the indentation is with respect to the orientation.

It’s also obvious that the firing pin indentations are pretty shallow. The indentation will usually be deeper as a result of the recoil of the case against the firing pin when a round is actually fired, though, so I’m not sure what to make of those examples. I still suspect that a somewhat light strike coupled with an off-center hit could make failures to fire more likely.

And I wonder why the bases of the reload cases sit proud above the case gages. It it’s because the brass is too long, that shouldn’t affect ignition reliability if the slide goes into battery properly. But if it’s because the cases should be resized a bit tighter, then perhaps what’s happening is that the case mouth doesn’t contact the front of the chamber firmly and properly, and the case is held in its initial position by its slightly oversized circumference. In that situation the force of the firing pin against the primer might be reduced because some of the energy is absorbed by driving the case farther into the chamber. I believe it would be best if the cases were resized so they dropped fully into a case gage. All that is of course questionable because the reloads seem to fit properly in the barrel chamber. I would nevertheless consider the resizing question.

But switching barrels and/or slides around might provide more clues.

quote:

And I wonder why the bases of the reload cases sit proud above the case gages. It it’s because the brass is too long, that shouldn’t affect ignition reliability if the slide goes into battery properly. But if it’s because the cases should be resized a bit tighter, then perhaps what’s happening is that the case mouth doesn’t contact the front of the chamber firmly and properly, and the case is held in its initial position by its slightly oversized circumference. In that situation the force of the firing pin against the primer might be reduced because some of the energy is absorbed by driving the case farther into the chamber. I believe it would be best if the cases were resized so they dropped fully into a case gage. All that is of course questionable because the reloads seem to fit properly in the barrel chamber. I would nevertheless consider the resizing question.

The case gauge issue is because the bullets are bottoming out against the shoulder in the gauge. They're 135gr powdercoated cast, with a kind of wide ogive, so it's either that or seat them super deep into the case, which I'd rather not do. They aren't touching the lands, as they pass the plunk test, and the rim is bottomed out aginst the front of the chamber...which is why the "headspace" measurement is the same for the reloads and the factory ammo, even though they don't pass the gauge.

I had a few minutes at the range this afternoon after shooting the new J-frame, so I stuck the upper from my P229 SAS on the P228 Frame. I dumped 50 rounds of this same ammo through it without a single failure, so I'm pretty confident the problem is in the upper.

I agree that the off-center firing pin strikes are concerning. The barrel appears to be locking up completely, though, so I'm not sure how one would go about adjusting it one way or the other. I also just looked at some of the primers on the spent cases fired from my P229, and the dimple is similarly offset on all of them, and they all went bang.

It could also be an out of spec firing pin, but I'm thinking Chris hit the nail on the head with the headspace.

Does anybody have the factory spec for firing pin length and headspace measurements for the P228?

If the headspace is off, can anything be done to fix it besides replacing the barrel? It doesn't seem like there's enough material left to do any fitting without compromising the lockup.

Slightly off center firing pin strikes on the primer should not make a bit of difference on a failure to fire condition with a hammer fired pistol.
With a striker fired pistol, that may not be true.
Some years back I purchased a brand new stainless steel Colt Gold Cup Trophy National Match 1911 from my local FFL.
The firing pin strikes on the primers were off center an obscene distance.
I sent it back to Colt and they replaced the slide.
See the photo below, which was before the Colt repair attempt.

When it returned from Colt it was slightly more centered, but still was far beyond what I considered normal and/or acceptable to me.
I traded that Colt Gold Cup pistol away after the Colt repair attempt.
It was a crying shame, as that Colt Gold Cup was the most accurate and reliable factory stock 1911 pistol I had ever purchased.
My multiple experiences with Kimber 1911 pistols that wouldn't run on multiple brands of factory 230 grain ball ammo, and the off center Colt Gold Cup made me switch to Dan Wesson 1911's.
So far I have not regretted switching over to Dan Wesson 1911's.

My point is, even with the firing pin strikes nearly to the edge of the primer cup, this Colt Gold Cup 1911 experienced zero problems with a failure to fire condition.

Gold Cup by cee_Kamp 32ACP, on Flickr

This message has been edited. Last edited by: cee_Kamp,

If that P228 was mine, the first thing I would do is go shoot some of the reloads that you are experiencing the failure to fire condition. Shoot until you experience your typical failure.
Then immediately switch ammunition to some recently manufactured factory loaded Winchester/Speer/Federal.
Try that and let us know how that ammo substitution test works out.

I need to get my hands on some factory ammo...I have to stop by the LGS for a transfer tomorrow so maybe I can pick up a box while I'm there.

Took it to the range again today with the regular reloads (CCI Primers), identical reloads with Remington 5 1/2 primers that I recently found locally, and a box of WWB 115gr. I put about 35 rounds of the Remington-primed stuff through it with no issues, then switched to the CCI primed reloads and immediately started getting light strikes. Switched to the WWB and got more light strikes, then back to the Remington-Primed reloads, which worked fine.

Clearly, the Remington primers are easier to set off. I ran that batch of ammo through the press without adjusting anything, so they are exactly the same as the CCI-primed loads, other than the primer.

The fact that it's not firing the factory WWB makes me not want to blame the ammo at all, though.

You do have an accurate conclusion now.

It appears to be a gun problem.

If I recall correctly, back in the old USPSA competition days, we always considered Winchester primers as the hardest, CCI in the middle and Remington as the softest.
With newly manufactured primers today, it's anybody's guess.

If your breechblock is pinned securely, firing pin is in good condition and adequate length, and the firing pin block is timed correctly & lifted up high enough so it doesn't drag on the firing pin as it is driven forward by the hammer impact/inertia, it appears you need more mainspring.

It's easy enough to change out a mainspring to the next step up, and retry the ammo substitution test.

Another possibility is a firing pin spring that is excessively strong, perhaps incorrect for the application?

Colt Series 80 1911's have a little steel finger that rises up out of the frame and lifts the firing pin safety plunger up in the slide when the trigger is pressed.
Those fingers were available in different lift height increments to be able to adjust for different machining tolerances/tolerance stacking.
The SIG system is different in construction, but operates in a similar manner.

Another way to test that for sure is to remove the firing pin block from the slide on a temporary basis strictly for diagnosis. Don't forget to reinstall after testing.
Go repeat your ammo/primer test with the firing pin safety block removed.
It's possible to have worn components, or a tolerance stacking problem even on a SIG.
That will tell you if the firing pin safety is dragging on the firing pin.

Firing pin and safety block timing seems to be testing ok.

I stuck a 28lb mainspring in it this afternoon (kind of a PITA, especially with the old style pinnned strut, but my kids are getting adept at becoming my extra set of hands at the vice, lol) and will test it again tomorrow to see if will shoot reliably. This isn't really the fix I'm looking for, though, as the DA pull is now insanely heavy. I really think it's a headspace problem and not a spring problem, I'm just not dying to spend $200 on a new barrel for a gun I'm already upside down on, especially without knowing what the actual factory measurements are supposed to be.