quote:

Originally posted by roboster2013:
Also, the edge of the striker foot which has a height thickness of approximately 2mm, is only making contact with approximately .25 of a mm of the leading edge only of the disconnector hook. Since the striker has been changed with a lighter weight version during the “upgrade program”, it is quite possible that any abrupt movement or twisting of the P-320 while holstered, could cause the foot of the striker to disengage itself from the disconnector hook on its own since there is so little contact between the striker foot and the [sear]." In a subsequent interview with a Boston news station, Viillani also stated "'Either Sig Sauer or their subcontractors, who made the parts for them, never finished the parts,' Villani said. 'They basically put the parts in raw so that the surface contacts weren't very finely tuned, so that would cause slippage.' So, since you too are a Sig armorer, I would be very interested in your take on MAJ Villani's conclusions.

quote:

Originally posted by SgtGold:
I'm having a hard time believing that Sig would design a handgun with that small of an engagement surface on a critical interface. .25 mm is 1\64 of an inch. That's not an engagement surface, it's shim stock. There has to be a mistake in the numbers.

quote:

Originally posted by roboster2013:
Also, the edge of the striker foot which has a height thickness of approximately 2mm, is only making contact with approximately .25 of a mm of the leading edge only of the disconnector hook. Since the striker has been changed with a lighter weight version during the “upgrade program”, it is quite possible that any abrupt movement or twisting of the P-320 while holstered, could cause the foot of the striker to disengage itself from the disconnector hook on its own since there is so little contact between the striker foot and the [sear]." In a subsequent interview with a Boston news station, Viillani also stated "'Either Sig Sauer or their subcontractors, who made the parts for them, never finished the parts,' Villani said. 'They basically put the parts in raw so that the surface contacts weren't very finely tuned, so that would cause slippage.' So, since you too are a Sig armorer, I would be very interested in your take on MAJ Villani's conclusions.

quote:

Seems rather small to me as well, but that is the figure that is quoted in the lawsuit filing. One other question is, if accurate, is that common to all 320s manufactured, or is it just common to some? Do we have a design flaw affecting all 320s, or a manufacturing flaw that only affects some 320s? If it is the later, it could explain why we haven't seen widespread wholesale unintended discharges with the 320.

quote:

Originally posted by 92fstech:

quote:

Seems rather small to me as well, but that is the figure that is quoted in the lawsuit filing. One other question is, if accurate, is that common to all 320s manufactured, or is it just common to some? Do we have a design flaw affecting all 320s, or a manufacturing flaw that only affects some 320s? If it is the later, it could explain why we haven't seen widespread wholesale unintended discharges with the 320.

Are you hearing anything that anyone is saying here?

Once again, the document states that Maj. Villani is an armorer. The Sig armorer class does not train an individual to evaluate the tolerances of parts the gun beyond the point of basic function, only to test function and replace parts as needed. I can't verify that the major measured properly, nor can I speak to the proper spec for that engagement surface, as this is not something that an armorer is trained on.

I don't see where it says anything about Maj Villani being able to replicate the problem, or in any way to induce the striker hook to slip off the sear while the gun was assembled. Nor do I see him addressing the issue of the striker safety and how that would have been defeated without the trigger being pulled in order to allow the gun to fire. These would be the things that an armorer should be looking for. Instead, all I see is him speculating about one measurement without replicating the supposed issue, or even comparing his observations to the factory spec for the engagement surface.

I would assume that as part of this investigation the gun would have been evaluated by an engineer, either from Sig or someone independent. Where are the results of that report? I'd like to see evidence from someone with the appropriate qualifications stating whether or not the gun is out of spec, replicating the issue, and explaining the full sequence of events that allowed it to discharge without the trigger being pulled.

Absent that, I find it much more plausible that the officer in question either pulled the trigger himself, or allowed it to be pulled by some other foreign object through negligent handling.

quote:

It would be great if there was someone in the sigforum community who actually knew the answer to the engineering questions that have been posed.

quote:

Originally posted by stoic-one:

quote:

It would be great if there was someone in the sigforum community who actually knew the answer to the engineering questions that have been posed.

I'm MORE than certain there are a couple people here that could answer the questions, will they is the real question. There's a better than 50-50 chance those very people may be queued up to actually testify or submit documentation if it becomes necessary.

quote:

Originally posted by Grayguns:
What is a "disconnector hook"? Who writes this drivel?

The net sear engagement height of post-voluntary upgrade P320's is nominally 1mm, or about .040".

-Bruce

quote:

Originally posted by Grayguns:
What is a "disconnector hook"? Who writes this drivel?

The net sear engagement height of post-voluntary upgrade P320's is nominally 1mm, or about .040".

-Bruce

quote:

Originally posted by sox:
Meaning only 1mm of contact before bam? How much variance is there? What are some other sear engagements in other brands I wonder. May be just fine but it doesn’t sound like a lot?

quote:

Originally posted by toto:

quote:

Originally posted by sox:
Meaning only 1mm of contact before bam? How much variance is there? What are some other sear engagements in other brands I wonder. May be just fine but it doesn’t sound like a lot?

Look at the Glock the sear engagement is no more important, disassemble the rear plate of the slide and you can see that.

quote:

Originally posted by sigfreund:
The question about how much contact there was in the P320 firing mechanism to prevent the striker from being released without pulling the trigger piqued my interest.

The striker pin is held to the rear in the cocked position by the sear that engages the striker pin lug. When the trigger is pulled, the sear is rotated down and the striker released.

The first photo shows the primary engagement surface of the sear circled in yellow. After the Dykem was applied, the slide was put on the gun and the trigger pulled one time. By the rub mark below the sear hook it appears that the lug engages the full height of the sear hook. That seems to be confirmed by the mark on the striker pin lug in the second photo.

I have no way of precisely measuring the height of the sear hook, but using a small rule it’s a bit over 1 millimeter (~0.04"), or just as Bruce Gray reported.

The blue ellipse circles the second engagement hook of the sear that would capture the striker pin lug if it slipped off the primary hook.

Sear:



Front surface of striker pin lug that engages the sear: