P320 back from Sig, with thoughts and before and after pics

[marine6680]

I received my 320 from Sig, it took two weeks a few days to get back into my hands for the "upgrade" program.

Some observations...

The trigger pull is different. Not bad, but it is not the same. A bit more creep now, but a bit less overtravel than before. The skinny trigger looks a little odd to my eyes, but is comfortable.

The sear is different, and has a second safety notch to catch a slipped striker.

The striker block is a simpler piece than the more complicated MIM part from before. It is just a flat sheet, possibly a stamped part. The striker block spring is stronger than before.

The striker was changed, and has a slightly different shape for the tang that has the sear surface.

Dry fire now requires a full cycle of the slide to reset the striker. I know why this is, more on that in a bit.

The disconnector does not function as an out of battery safety... I know why though, more in a bit... This may also come back and bite Sig. I can't recall if there was out of battery safety function before, but I think there was...

They milled out the slide in two places to accommodate the disconnector...

In the rear of the slide where the disconnector sits when the slide is in battery... And a little farther forward, to allow the disconnector space when the slide travels forward. This area only needed a slight tweak, as the space was not flat, and had a slight ledge. They just removed that small ledge.


Now this milling and the disconnector are the culprits behind the above points... The slide needing a full cycle to reset the trigger and no out of battery safety.

The reason is due to the fact that this is a retrofit.

The slide had troughs cut into areas of the slide to help lighten it... The trough on the disconnector side of the slide is the single factor. The trough extends from the point they had to mill in the rear, and stops just aft of where they had to mill in the front.

The disconnector is activated by the front edge of the trough. The edge acts against the ramped surface of the disconnector. The trough has a radiused shape at the front, not flat and squared off.

This is not an ideal shape to act against the disconnector... But it is what it is, as it existed before the retrofit.

This is why you need a full cycle to reset the trigger... As the trough is so long, that you need that much movement before the disconnector is activated.

This is why there is no out of battery safety function... there is no surface to push the disconnector, and disable the trigger until the slide cycles fully.

And I did test this... And you can drop the sear with the slide well out of battery.


I would believe that this is not a problem on new 320s that have these updates as standard from the factory... Just eliminate the trough, or a portion of it, to allow a smaller cutout section for the disconnector, so it is activated more quickly. Providing most importantly... An out of battery safety. (looking at the Sig info video, I believe this is in fact the case, but contrast is too low for me to be 100% on that)



I have some before and after pics. you can see the changes and see the milling of the slide. This should give a good picture of what I am talking about.

Before Pics

[marine6680]

More before

[marine6680]

After

[marine6680]

More after... Notice the milling, and the trough. You can see the spot where the disconnector hits the front edge.

[TunnelRat]

The slide had troughs cut into areas of the slide to help lighten it... The trough on the disconnector side of the slide is the single factor. The trough extends from the point they had to mill in the rear, and stops just aft of where they had to mill in the front.

The disconnector is activated by the front edge of the trough. The edge acts against the ramped surface of the disconnector. The trough has a radiused shape at the front, not flat and squared off.

This is not an ideal shape to act against the disconnector... But it is what it is, as it existed before the retrofit.

Are you saying the slide had troughs beforehand (that is what the pictures seem to show)? Because my 9mm Compact has no troughs as shown in these pictures. FWIW I've noticed the milling on this P320, packaged date of 12/24 of last year, has notably different milling than the early P320 I had.

And I did test this... And you can drop the sear with the slide well out of battery.

You know more than me in this area, but looking my pistol with the slide off it seems like if the slide is out of battery the striker block won't be depressed properly and even if the sear releases the striker then the striker block should serve its function. As it is currently my pre-update pistol can also drop the sear with the slide out of battery.

[marine6680]

That may be the case.

So it may be moot... But if the pistol is not fully in battery, even a small amount, its not good if the round goes off.

I doubt the pistol will fire with the case exposed... A true out of battery.

But it could fire with the slide partially unlocked, but still forward enough to allow the striker block to be deactivated. It looks like there is about 1/8 to 3/16 of an inch you can move the slide and still get enough activation of the striker block for the striker to travel fully.

Not likely to be catastrophic, but it can cause damage, as the action isn't locked properly.

I also could be completely incorrect in my assessment... In which case, its no big deal, and I am being overly paranoid. With a modified firearm, I want to be a little cautious, not overly so.


And it would make sense that a compact would be a bit different. The slide already weighs less than the full sized.

But I would not be surprised if the full sized was changed after the early ones... There are a lot of odd angles and relief cuts that seem excessive in my early production 320.

[marine6680]

Tested further...

The slide can be out of battery a bit over 1/8 of an inch and still allow the striker to fully travel with good force.

Looking at side of the slide, when the begining of the first (or last depending on how you look at it) cocking serration is even with the rear of the frame, that is the limit. More than that and the striker does not impact.

That is right at the point the barrel starts to drop out of lock.

[TunnelRat]

But I would not be surprised if the full sized was changed after the early ones... There are a lot of odd angles and relief cuts that seem excessive in my early production 320.

I remember those on my previous compact model, notably what were like a series of steps in the interior of the slide near the front of the barrel (kind of made cleaning a pain). Those are gone now on my newer compact.

[Mackie244Bud]

I believe that "marine6680" has a 45 and Slide milling is different than the 9mm.

Mackie244Bud

[WVsig]

Any area that is finished not silver is original to the gun when it left the factory the first time. The trough was present on this slide when it originally shipped.

[WVsig]

Here is a pic of my 45 fullsized slide. There is no trough.

[marine6680]

Yeah, mine is a 9mm early model.

The trough was always there, I suspect to lighten the slide a bit.

The silver contrast of the milled areas, make it easy to see where they did the work.

Seems your 45 has the disconnector original from the factory. When did you purchase that pistol? Is it newer?

[WVsig]

Originally Posted by marine6680

Yeah, mine is a 9mm early model.

The trough was always there, I suspect to lighten the slide a bit.

The silver contrast of the milled areas, make it easy to see where they did the work.

Seems your 45 has the disconnector original from the factory. When did you purchase that pistol? Is it newer?

IIRC it is a late 2015 gun.

[marine6680]

So... I wonder when they first started using the disconnector, and was it only the 45 at first...

[WVsig]

Originally Posted by marine6680

So... I wonder when they first started using the disconnector, and was it only the 45 at first...

My slide was definitely milled to accommodate the disconnector.

[pblanc]

Early 9 mm P320 had lightening cuts routed into the bottom of the slide on both sides, a long one on the right, and a shorter one closer to the breech block on the left. This was done to allow the use of very lightweight frangible projectiles but was found to result in excessive slide velocity causing failures to extract/eject with some P320s.

A later version just had the two cylindrical holes drilled in the bottom left side of the slide near the breech block, instead of the longitudinal rout, and no cut on the right side.

Other P320 slides have no lightening routs or holes at all.

Only the newly modified P320s have a disconnector. All modified P320s have a small "divot" routed on the bottom right side of the slide at the back to accommodate the disconector.

[TunnelRat]

^good info. Anecdotally I have had fewer failures to extract with this P320 than my first. Additionally it has had no issue running frangible, though the frangibile I use is pretty hot.


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[Mackie244Bud]

TunnelRat says

I have had fewer failures to extract with this P320 than my first.

I have put over 1,000 rounds through my P320 Compact RX without 1 failure at all, of course I am not using "Frangible Ammo."
What ammo are you using?
Maybe you have actually found ammunition that the P320 doesn't like.
Which that would be a first too!

Ammunition I've used:

Range Ammo:

Remington 115g & 124g FMJ (green & white box)
Blazer Brass 115g & 124g FMJ
Federal "American Eagle" 124g (because of their Ammo rebate)
However I am very happy with Federal Ammo!

Defense:
SpeerLE Gold Dot 124g HP

Just got my P320 back from Sig's "Voluntary Upgrade" but I have not been to the range yet.
Hopefully tomorrow.

Mackie244Bud