Overtravel and dwell time.

[shortine]

I'm confused about the trigger bumping the stop having an effect on accuracy. Hasn't the bullet left the barrel by then? In order to hit the stop with the bullet still in the barrel, wouldn't you have to be Superman...."faster than a speeding bullet"? I'm sure someone has done some definitive testing with sophisticated equipment, and there's some discussion somewhere on the topic. Point me the way.

Thanks,

Gerry

 

[rardoin]

Keep in mind that the projectile is not travelling at MV for the entire length of the 'internal' path. It starts from '0' fps and accelerates until it transits the muzzle. More time available for me to 'f' up a release than one might think.

Robin

 

[Ned Ludd]

Barrel occupancy times for a typical centerfire rifle might be in the 1 to 2 millisecond range (i.e. 0.001 to 0.002 seconds). That may not seem like a lot of time for your finger to pull the trigger all the way back to the stop. However, compare that to a typical .22 rimfire setup, which is likely to have barrel occupancy times of something more like in the 3 to 5 millisecond range. I can tell you for a fact that with my rimfire target rifle, I have to noticeably hold the reticle on target a moment longer than with my centerfire rifles, or the shot will be pulled. If the barrel occupancy time is enough longer to be noticeable in terms of maintaining your hold and position, I can imagine it might be long enough that the trigger pull comes into play, as well.

 

[JMayo]

I to am confused about this. A bench rest shooting friend talked that he could tell the way the butt hit his shoulder what the bullet was gonna do.
..I thought bs ...
But now I know it does matter.

All the science in the world can't explain it to me so I "get it" but from my own experience I'm a believer...

 

[D-4297]

How many times were we all told as beginners , that we "Pulled" a shot , to 7 o'clock . ( right-handed ) If it had no effect , then why do we have triggers with such light pull weights ? To remove the "pressure" of the trigger pull affecting our shot . Shooting a L/R precision rifle like a pistol , will get you a lot of "Pulled" shots .

 

[Doug Beach]

As a decent sling shooter, I often get asked “how do you guys do that with iron sights?”
I tell ‘em it’s not what you see, but what you do with the trigger.

 

[Papa Charlie]

Good statements above.
Keep in mind that you have actually released the firing pin well before you contact the end of travel.
Add this to the time it takes our brains to analysis the release to the EOT, plus the expansion of the gases as the powder ignites, plus the build up of pressure behind the bullet, plus the acceleration of the bullet from zero to MV and you would have to admit that there has been a significant enough impact of your finger angel on the trigger, finger to trigger smoothness, cheek pressure, shoulder pressure, body angle, and recoil to have an effect on the bullet POI.
I think that there is a very good possibility that your striking the trigger EOT could have a significant effect on you POI.
JMHO
Patrick

 

[dc.fireman]

As a decent sling shooter, I often get asked “how do you guys do that with iron sights?”
I tell ‘em it’s not what you see, but what you do with the trigger.

I agree with @Doug Beach, 100%.

One of the things I focus on more than anything when shooting irons, is shot execution. I have also moved away from a two stage trigger, in favor of the lightest possible single stage trigger I can safely use. The change in the geometry of the hand after taking up the first stage can cause slight delays in breaking the shot, and even cause the rest of the hand to squeeze the grip inadvertently, influencing the shot break.

Routinely when shooting prone, and standing, I will hold the trigger rearward after the shot breaks for a full two second period. A buddy of mine actually advised to 'hold the shot so long, that you think people might be laughing at you."

His advice has helped me tremendously in the past half year. Consistent finger placement on the trigger, along with shot execution are critical to high scores.

For giggles and grins, the next time you go out to shoot, try changing the placement of your trigger finger on the trigger at five shot intervals. Then try changing your wrist angle from fairly straight, to fairly bent. You may be surprised at how far the shot breaks away from the previous five shot group.

-tc

 

[HTSmith]

I turn the overtravel screw on all my Jewell triggers all the way in (maximum overtravel). It seems to have helped with fliers, but I can't prove that.

 

[Dusty Stevens]

^this.
The trigger that “breaks like glass” will never shoot with the sloppy trigger with a ton of overtravel.

 

[TAJ45]

Dusty, need you to 'splain your statement more better. I MUST be reading it wrong, as an occasionally competitive BE shooter "back in the day". Make it Crayola simple for me please.

 

[Dusty Stevens]

Dusty, need you to 'splain your statement more better. I MUST be reading it wrong, as an occasionally competitive BE shooter "back in the day". Make it Crayola simple for me please.

When you set the sear engagement and the overtravel to where its perfect and you get the proverbial “break like a glass rod feel” it doesnt shoot as good as one with overtravel for follow thru. The ones with the overtravel set tight will invariably stop working for you at the most inopportune time. Is that crayola enough?

 

[TAJ45]

Thank you. Not my experience w my 41s or Giles hvy slide. My smith/coach had things at minimums for self and the other club guns given to him for trigger jobs, never a failure at club or at a match. And yes the triggers "broke like glass".
I guess all mileages can vary.

 

[Dusty Stevens]

Thank you. Not my experience w my 41s or Giles hvy slide. My smith/coach had things at minimums for self and the other club guns given to him for trigger jobs, never a failure at club or at a match. And yes the triggers "broke like glass".
I guess all mileages can vary.

Talking rifles here with sub 2oz 3 lever triggers. Longer barrel time and way less weight on the trigger then coming to an abrupt stop

 

[swd]

Don't worry about over travel and dry firing feel. I've found that with anything pretty light as in 1.5oz to 1lb you don't even notice the over travel backed way off when the rifle fires.

 

[TAJ45]

The additional parameters make sense Dusty.

 

[natdscott]

The additional parameters make sense Dusty.

TAJ4, are you going to that RF sporter match coming up?

If you want, you can judge how a few of my rifles are set up.

I “stone” my trigger’s internal bearing surfaces by hand on a surface plate until all visible striations are oriented perpendicular to the break. I am at about 3,000 grit, and that’s plenty, because if you mate them too closely, the opposing metal gets grabby, and you can’t keep any grease in between to stop it.

I don’t change the angles, I just make the trigger movement in “takeup” or “roll” virtually imperceptible.

I want the trigger to then break extremely sharply with no grit, catch, or warning.

When it breaks, I no longer care about the trigger, as it’s done it’s job, I just don’t want it to slam into the backstop of an overtravel screw and generate movement.

As such, NONE of my triggers except the 41 are setup with a short overtravel. Not one. That’s 10m air pistols, Anschutz silo, hunting Jewells, and yes, my Service Rifle. 100 grams through 5 lbs, Single, Two stage, and set triggers.

The biggest variance I have between my triggers is sear engagement. I don’t set field rifles really light, nor really short on engagement. I’ve proven to myself what I can do with a nearly 5 lb, extremely slow locktime Geissele, and I know I cannot shoot 1/4 minute in the woods, nor are those rifles capable, so why push limits? The best and most used .243 is a carefully maintained HVR at 3 lbs, with “some” roll, and the overtravel screw is just there to keep dust out.

Target single stages are set pretty fine on engagement, but I still have a little roll...it just doesn’t give your finger much feedback that it is, in fact, moving.

As I’ve pursued precision offhand, my thoughts on triggers have changed, and those trigger changes have helped all the rest of my shooting as well.

Then again, so does air pistol.

 

[BoydAllen]

Recently I saw a video of a fellow shooting a benchrest rifle. It looked like he had the end of his thumb against the middle of his trigger finger in a way that restricted its bending to the first joint. I may have to try that on my light triggers. IMO when a chosen but transient flag condition occurs, there can be a tendency to rush the pull and apply more force than is necessary. This is one reason that I try to remember to do some dry firing at the beginning and again at the end of range sessions.

 

[Brians356]

Recently I saw a video of a fellow shooting a benchrest rifle. It looked like he had the end of his thumb against the middle of his trigger finger in a way that restricted its bending to the first joint. I may have to try that on my light triggers. IMO when a chosen but transient flag condition occurs, there can be a tendency to rush the pull and apply more force than is necessary. This is one reason that I try to remember to do some dry firing at the beginning and again at the end of range sessions.

So position the thumb to limit overtravel of the trigger finger? Interesting...
-

 

[BoydAllen]

So position the thumb to limit overtravel of the trigger finger? Interesting...
-

It looked that way to me.