Longer Barrels Exacerbate Pre-Ignition Push?

[JCN]

I agree in a way and suppose that it's a psychological reason. The G17 has a longer sight radius than the G19. So the G17 makes differences from a perfect sight alignment more visible. Then with a G17, the shooter wants to aim too well. And when he finally achieves the perfect sight alignment, he pulls the trigger to fast and significantly destroys perfection before ignition. The fraction of a millisecond in the barrel post-ignition does not cause the problem.

Remedy according to this hypothesis: Accept a non-perfect sight picture according to the distance and size of the target. You only need a good enough sight picture.

What are these “iron things” that you speak of?

Sincerely,
Dot shooter

Most of the time the error is actually some function of “anticipating recoil—> flinch” rather than something to do with the sight picture / vision, AFAIK.

[P30]

What are these “iron things” that you speak of?

OK, good point. MarkD did not mention what kind of sight he uses (iron or red dot). If he uses a dot, my hypothesis is falsified.

Jerry Miculek said: "Trigger press is more important than aiming." Sometimes I'm in danger of aiming too well. Then I switch and consciously do what Jerry recommends: Focus less on aiming - et voilà - POI is better. If I want to aim too well, POI is worse.

[Caballoflaco]

What are these “iron things” that you speak of?

Sincerely,
Dot shooter

Most of the time the error is actually some function of “anticipating recoil—> flinch” rather than something to do with the sight picture / vision, AFAIK.

Yeah, I think this is more his nervous system being timed for the 19 vs 17. I bet a few range trips with the 17 would sort things out. But this can be related/activated by the visual signals to the brain. For example I had a period in my archery where I had no, zilch, zero physical control of when I released an arrow as soon as it neared the target.

[Mark D]

Thanks for the good feedback. I won't try to respond to everyone's input, but here's a few replies and some additional context.

Regarding sight radius and sight picture, I should have specified that both guns are equipped with direct-milled dots. I'm all-in on the dots now.

Is it possible that grip length and changes in how you’re imparting forces on the gun with a different grip and shape are as much or more an influence than barrel length? The hump on a 17 causes it to push in my hand a lot differently than a 19.

A G17 is 0.5” longer than a G19. At 1000ft/s, or 12000 in/s, a bullet is spending an extra 1/6000 of a second, ~0.00017 sec in the barrel. Thats not much time…

Agreed, 1/6000 second it not much time at all... On the subject of grip length - it can make a difference, for sure. I noticed that with the G26 - the short grip meant that it was immune to my pinky tightening when I pressed the trigger. But I can get a full firing grip on the G19, so I don't think the grip length is why the G17 is performing differently for me.

I have not noticed this, in fact for me it'd be the opposite. If I'm shooting for max speed + accuracy on demand with the least likelihood to anticipate recoil, my order of preference would be something akin to:

G34>G17>G19>G43

The long slide and the mass thereof cycles slower, reduces felt recoil and provides more information when shooting irons.

I'd suspect two things are happening if shooting short slides and frames more accurately (with irons), both mental. One, there's less information coming from the sights, meaning there's less potential for one to snatch for a perfect sight picture and secondly there's less of a tendency to tighten your strong hand pinky finger and push shots right (or left) on a gun with a shortened grip, particularly one where you can't get a full hand on the gun.

From an objective data perspective, if I had to look back over the years at old USPSA production division stats of people shooting at a (very) high level, I don't think I'd find many short slide guns at the top of the list. Competitors being what they are, if a short slide offered even a small advantage, you'd see the equipment moving that way.

Good point about the USPSA stats. I haven't looked, but it seems like the longer barrel guns really dominate, even in the dot divisions. That said, most of the really good competitors don't seem troubled by pre-ignition push. They're either not susceptible, or have long since trained through it.

@Mark D I would probably flesh out your model.

There’s not time for the barrel length to make a meaningful contribution.

But muzzle weight x distance from the fulcrum and balance of the system can matter.

Very heavy dust covers / flashlights can weight the gun more towards the nose and with poor trigger follow through can cause a dip.

But here’s the flip side. More mass there if supported… helps prevent pre-ignition push.

So it comes down to shooter mainly.

The trigger and grip hump location in your situation are probably your main contributions.

You can test this yourself by later running a G45 versus a G47 type gun.

If you’re talking about tracking under recoil that’s a different thing. But the actual pre-ignition push for a trigger… barrel isn’t going to contribute as much as the grip hump location and the trigger weight.

IMO

I suspect you're right about the differences in trigger being at least part of the problem. I have parts inbound to make the triggers (near) identical. But I don't follow how the difference in hump contributes. The hump does make a noticeable difference in presentation - the G17 presents flatter and I acquire the dot earlier, but I'm not sure how that plays into the pre-ignition push.

Lock time has far more impact than ignition or barrel dwell time in terms of the human interface factor with any kind of shooting.

Hammer driven ignitions have longer lock times than striker ignitions, for example.

If you are already in motion as the hammer or striker drops, all else being equal, the striker gun will have an edge in accuracy. On paper.

However, in the real world, with modern firearms, dwell time is about 1/10th of lock time, and the two together are still about 100 times faster than any human reaction.

As a practical matter I would suggest learning to correctly shoot a smooth DA firearm- particularly a revolver. In my experience, that is a powerful tool for solving the sort of problem you describe.

Interesting points on the lock time and dwell time. I've a bit of time behind revolvers and I have about 10,000 rounds through LEM guns, which are almost DA. I also spent a season with a PX4, including a class with EL, so I'm not a complete stranger to hammer fired DA guns. But for me, I'm not sure any of that work transfers to shooting striker-fired pistols.

@Caballoflaco could well be right - my system is just synced up with the G19 and more live fire with the G17 will smooth things out. I'll update the thread once I get the triggers cloned and get back to the range.

[JCN]

I suspect you're right about the differences in trigger being at least part of the problem. I have parts inbound to make the triggers (near) identical. But I don't follow how the difference in hump contributes. The hump does make a noticeable difference in presentation - the G17 presents flatter and I acquire the dot earlier, but I'm not sure how that plays into the pre-ignition push.

It can change the palm to trigger reach and angle slightly and also feel somewhat more foreign if you’re counting on certain physical cues to trigger your timing. Those cues will be mis-timed if the ergos are different.

This is the reason why I’m not a fan of the “only train with one gun” mantra.

I had this experience racing cars. You can develop certain compensations that are specific to one system and they don’t hold with other vehicles and systems. And you don’t notice when you’re training with just one… until you get to another.

What your body cues in on may not be as universally applicable as you think or like.

For example, when I spent almost all my time on high revving normally aspirated engines, accelerator position was linear with acceleration and I was also cuing on engine pitch.

When I went to turbo engines, there was an added variable of spool and boost to manage and the acceleration was now not linear anymore with pedal position. So my mental cuing had to get more robust and rely more on my inner ear and vision for the acceleration and speed assessment.

Something like that may be happening with the hump position of the G19 versus 17.

It is basically a training issue.

[mizer67]

....if you’re counting on certain physical cues to trigger your timing. Those cues will be mis-timed....

While not specific to the short slide vs. long slide discussion, I definitely see this switching platform to platform and trying to shoot to a very high level.

I put a very high % of my rounds through Glocks, unless I'm evaluating a new gun. I also have the same trigger set up in each, except the slim frames which are a bit different in how they feel no matter what components are utilized.

I can shoot very well....with a Glock. If I pick up another gun, my timing is off and with it my shots. If I then go back to shooting a Glock, I have to re-adapt a short while to get back to 100% of my prior abilities. With some guns this gets masked by a heavy gun and light trigger, but it's still present somewhat. While I can shoot many guns passably, for me with my time and ammo budget to be much good I have to focus.

[Mark D]

It can change the palm to trigger reach and angle slightly and also feel somewhat more foreign if you’re counting on certain physical cues to trigger your timing. Those cues will be mis-timed if the ergos are different.

This is the reason why I’m not a fan of the “only train with one gun” mantra.

I had this experience racing cars. You can develop certain compensations that are specific to one system and they don’t hold with other vehicles and systems. And you don’t notice when you’re training with just one… until you get to another.

What your body cues in on may not be as universally applicable as you think or like.

For example, when I spent almost all my time on high revving normally aspirated engines, accelerator position was linear with acceleration and I was also cuing on engine pitch.

When I went to turbo engines, there was an added variable of spool and boost to manage and the acceleration was now not linear anymore with pedal position. So my mental cuing had to get more robust and rely more on my inner ear and vision for the acceleration and speed assessment.

Something like that may be happening with the hump position of the G19 versus 17.

It is basically a training issue.

Thanks for elaborating, JCN. That's a good analogy, and it makes sense when explained that way.

[Doc_Glock]

After shooting G19s exclusively for a year, I recently started experimenting with G17. With the G17 I am much more likely to push shots low when shooting under a little bit of time pressure (e.g. The Test, 5 Yard Round Up, etc.).

I noticed something similar several years ago when transitioning from very short pistols (G26 and a Shield 1.0) to slightly bigger guns.

My hypothesis is that shorter barreled pistols are more forgiving of mistimed attempts to control recoil. The bullet leaves a shorter barrel slightly sooner than a comparable longer barrel, and there's less time for human error to force the bullet off target. It's a matter of micro-seconds, obviously, and an issue that can be addressed with training, but I think it's a thing.

I am prone to pre-ignition push, but generally minimize it's impact on my shooting with regular dummy and ball drills, skip loading, etc.

A disclaimer - there are minor differences in the triggers between my G19 and G17. The 19 has an Overwatch shoe and a minus connector. The 17 has an Apex kit. They're similar but are not identical. In the interest of experimentation, I will setup the trigger in the G17 the same as the G19 and do more testing. I'll post results here.

I found that with longer barreled pistols (G34, Beretta M9 with Brigadier slide), I had difficulty controlling the forward dip of the pistol at the end of recoil when shooting fast leading to low hits in that situation. I am not exactly sure why but perhaps it was over compensation from controlling recoil. Regardless I found I had to shoot them slightly slower in order to get the timing right. Both of those pistols annoyed me enough with this issue that I eventually got rid of them. I suppose I could have adapted and or changed recoil springs to help that also.

[Mark D]

My hypothesis is that shorter barreled pistols are more forgiving of mistimed attempts to control recoil. The bullet leaves a shorter barrel slightly sooner than a comparable longer barrel, and there's less time for human error to force the bullet off target.

I concede that I was wrong on this. The issue I was experiencing was largely caused, I think, by the different timing of the two guns. So basically, ya'll were right.

Today I shot multiple iterations of The Test with the G19 and the G17. I chose this drill because it exposes my pre-ignition push. Both guns now have the same trigger components, and in dry fire feel very similar. Both guns are dot-equipped and have a 25 yard zero.

With the G19, I was able to shoot high 90's and a hundo in the 7.xx second timeframe. After recoil, the gun just seemed to be back on target and ready to shoot much faster.

I struggled with the G17. I was not in sync with the timing of the gun. Possibly because the slide was moving slightly slower, or the greater slide mass causes more muzzle dip when it goes into battery. A couple of times I found myself pausing and having to settle my dot. Although my scores were not bad overall (mid-90's and all in the black), my times were 1.5 - 2 seconds slower and my groups were lower on the B8.

I'd like to continue the experiment with a G45, as @JCN suggested, but they're hard to get in my locale.

ETA: tried to upload photos but P-F ain't cooperating tonight.

[mizer67]

Tuning the recoil spring makes a big difference in getting the timing right and reducing the muzzle dip from the slide slamming forward.

It's a real benefit for a competition gun to tune the recoil spring to the load, but understand not doing so for a duty gun.

G17's benefit from a 17 or even 15 lb. spring in this regard, if shooting factory target ammunition.