The PX4 Compact might be my DA/SA Glock 19

[joshs]

The spinning brass in the PX4C video is mesmerizing.

Hypothesis: the Glock has a heavier slide plus another ounce for the RMR. That leads to a heavier reciprocating mass. Is that a 17 or 19? Of course compensator should correct things.

It would be interesting to compare the PX4C to a non comped G26 with 12 round Magpul mag or some sort of grip extension.

I've shot a G26 a fair amount. I don't think the recoil impulse is comparable to the PX4 Compact. This is the first time I've watched myself shoot one on with good quality slow motion video, but it confirms what I see in the sights. The PX4C snaps back on target quickly with very little bobble/dip.

ETA: This was with PMC 9MM, so I'm not sure how effectively the ammo was running the comp. A hotter 9MM load may have made the Glock shoot flatter.

[JTQ]

The spinning brass in the PX4C video is mesmerizing.

Yes, I was likewise mesmerized.

I started paying attention to ejection patterns in all these on-line videos after the Glock ejection issues came up. It seems as if the guns with a longer extractor seem to give more consistent ejection.

[YVK]

i am strongly considering getting a PX4 compact carry. However, i have noticed with regular PX4 Compacts, that the single action trigger reset is very very inconsistent. sometimes after pulling the trigger and racking the slide, then releasing the trigger to the reset point is very short, on the order of about 2mm. other times, doing the same thing, the reset point is all the way at the beginning of the single action trigger travel, about 8mm. i have tried this with 6 different PX4 compacts, 4 new, 4 used. each one of them does this. does anyone else notice that the single action reset point varies quite a bit from being very short or as long as the full reset of the single action travel? this seems really unusual and really not ideal. anyone else notice this?

Both of mine are very consistent, and long. With videos above consistent with my own experience of PX4CC getting back on target really quick, I occasionally find myself still working the trigger/prepping when front sight shows a green light. Some of it is probably because I shoot Shadow 2 a lot where I don't need to be thinking about it at all, but it still annoys me regardless of a season.

[YVK]

Reason, not season.

[joshs]

i am strongly considering getting a PX4 compact carry. However, i have noticed with regular PX4 Compacts, that the single action trigger reset is very very inconsistent. sometimes after pulling the trigger and racking the slide, then releasing the trigger to the reset point is very short, on the order of about 2mm. other times, doing the same thing, the reset point is all the way at the beginning of the single action trigger travel, about 8mm. i have tried this with 6 different PX4 compacts, 4 new, 4 used. each one of them does this. does anyone else notice that the single action reset point varies quite a bit from being very short or as long as the full reset of the single action travel? this seems really unusual and really not ideal. anyone else notice this?

I'd guess this is almost certainly the firing pin block not resetting for some reason. On a PX4, like a 92, you can watch to see if the FPB drops down. If it doesn't, then the reset will be very short (like a Sig SRT). Maybe on a new gun there is a burr keeping the FPB from moving under spring pressure. None of my 3 PX4s do this, but mine all have at least several thousand cycles on the fire control components. The reset distance on a PX4 is almost the entire SA pull length, but, as EL mentioned, reset distance, like bore-axis height, is something that makes a very small difference in overall shooting performance.

[PX4 Storm Tracker]

I'd guess this is almost certainly the firing pin block not resetting for some reason. On a PX4, like a 92, you can watch to see if the FPB drops down. If it doesn't, then the reset will be very short (like a Sig SRT). Maybe on a new gun there is a burr keeping the FPB from moving under spring pressure. None of my 3 PX4s do this, but mine all have at least several thousand cycles on the fire control components. The reset distance on a PX4 is almost the entire SA pull length, but, as EL mentioned, reset distance, like bore-axis height, is something that makes a very small difference in overall shooting performance.

joshs, I would like to point out that the PX4, though similar, has some differences from the M-92 that would make the firing pin block plunger activity not affect trigger reset. The first evidence of the differences is that if you put the pistols on Safe or hold the non-stealth levers down, the firing pin block plunger on the M-92 will go up and down with trigger movement. The Storm’s will not. The firing pin block plunger is disconnected from contact with the trigger bar once the slide pushes the trigger bar down. The firing pin block plunger cannot affect anything but the firing pin’s movement if stuck upward or sticky.

To save space here, I reference a thread on how the PX4 trigger reset works: https://pistol-forum.com/showthread....-and-how/page2 Posts 19-22

How the trigger bar disconnects from it: https://pistol-forum.com/showthread....art-do-and-how Post 4

And how the firing pin block plunger affects things: https://pistol-forum.com/showthread....-and-how/page4 Posts 40-42

[joshs]

joshs, I would like to point out that the PX4, though similar, has some differences from the M-92 that would make the firing pin block plunger activity not affect trigger reset. The first evidence of the differences is that if you put the pistols on Safe or hold the non-stealth levers down, the firing pin block plunger on the M-92 will go up and down with trigger movement. The Storm’s will not. The firing pin block plunger is disconnected from contact with the trigger bar once the slide pushes the trigger bar down. The firing pin block plunger cannot affect anything but the firing pin’s movement if stuck upward or sticky.

To save space here, I reference a thread on how the PX4 trigger reset works: https://pistol-forum.com/showthread....-and-how/page2 Posts 19-22

How the trigger bar disconnects from it: https://pistol-forum.com/showthread....art-do-and-how Post 4

And how the firing pin block plunger affects things: https://pistol-forum.com/showthread....-and-how/page4 Posts 40-42

On all three of mine, if you hold the FPB up, the reset is about 2 mm as described.

[PX4 Storm Tracker]

On all three of mine, if you hold the FPB up, the reset is about 2 mm as described.

I will try that experiment on ours.

[PX4 Storm Tracker]

joshs, We tried that multiple times and were not able to have any change in trigger reset. I cannot explain why you are getting different results than we.

Next, we disassembled and isolated the firing pin block plunger's route. I thought that the next possibility is that the plunger getting stuck upward caused the plunger lever to stay stuck upward. We isolated that function and it did not affect trigger reset. We did everything we could to duplicate your results and could not.

[joshs]

joshs, We tried that multiple times and were not able to have any change in trigger reset. I cannot explain why you are getting different results than we.

Next, we disassembled and isolated the firing pin block plunger's route. I thought that the next possibility is that the plunger getting stuck upward caused the plunger lever to stay stuck upward. We isolated that function and it did not affect trigger reset. We did everything we could to duplicate your results and could not.

Are you holding the FBP up while racking the slide, then releasing the trigger slowly?

The trigger bar in my PX4s all reset off of the FBP safety lever. As soon as the slide disconnects the trigger bar into the fully "down" position, the safety lever moves all the way forward/down. The trigger bar then must come all the way forward to clear the leg on the safety lever to fully reset the trigger. If the safety lever doesn't move forward/down, then the trigger bar just resets off the sear. I'll see if can take a quick video to better demonstrate what I'm trying to describe.