Real Lock Time, Barrel Time, and On Call.

[brent375hh]

I just took delivery of a new Evo 10. I was shooting it better than my LP10, but it felt like it was shooting faster. I ran it across the chrono to find out it was averaging 562. It also only got about 87 shots on a cylinder at 170 Bar.

I don't hold still enough to just hold on an area and squeeze, my pressure adds when things look better. I have read many times how little there is on barrel time, but don't know how it was calculated. I have to think that it isn't simply mv /mv. The faster shooting gun has to also accelerate the pellet up to speed quicker. The increase on the striker spring also has to have the valve opening sooner under more tension. I think it would be very hard to simply calculate what the exact differences might be.

All I can say is that my groups were slightly tighter and more on call. I don't think it is all " new gun syndrome " either. Time will tell, as I like it, but might drop it down a tad. The test group with the gun is an outstanding small round hole that was assumed to shot with the gun shooting this fast.

[northpaw]

Thanks for your post. Of cource, barrel time does mattes. Imagine a lazer beam of zero barrel time....
According to Mr "W" of this forum barrel time does not matter. Howe emptysculled does it get? Just my asking.

Mr. j brent375hh you have just seen the light in practise.

[6string]

This may or may not be in keeping with what you describe, but I've been striving to reverse the "sights then trigger" approach to something more like the reverse.
Despite my best efforts at physical training, I doubt I'll ever become anything approaching a human machine rest. (Obviously not a realistic goal.)
For free and air, my attempts are to release the shot as soon as possible to when the sights come to bear on my ideal point of aim. This is before any tremors set in from over-holding. I might hold on a bit if there is a little shift, but anything more and I abort the shot. Preferably, my commitment to the trigger prompts any needed refinement in the sight picture.
The results have been interesting. The good shots are phenomenally tight, but the wild ones are disconcerting. Hopefully, that is a matter of adopting a new technique.
Nonetheless, I think it plays into the idea of mechanical accuracy (with issues like lock time, etc.) vs technique.
I'm not sure, but it seems like subtle differences in lock time and barrel time are rather minor compared to the mental processing and inherent errors of waiting for the perfect shot and then responding to it with trigger control.

Hope this isn't too much of a digression. Certainly not intended as being critical of what anyone else is doing. Just thinking out loud.

Jim

[william]

Thanks for your post. Of cource, barrel time does mattes. Imagine a lazer beam of zero barrel time....
According to Mr "W" of this forum barrel time does not matter. Howe emptysculled does it get? Just my asking.

Mr. j brent375hh you have just seen the light in practise.

Apparently spell check doesn't work in "old europe" nor, apparently, math or logic. The difference between the specified m.v. of an EVO10 and an LP10 is 37 feet / sec. which represents a 7% change. If the EVO10 barrel time is approximately 2.7 milliseconds, which is close enough for jazz, the lower velocity of the LP10 will increase the barrel time by less than 0.2 milliseconds.

I leave it to the troll who can't get me off his mind to explain how less than 200 freakin' MICROSECONDS makes a practical difference. I suggest it can't be done without invoking the number of angels dancing on the head of a pin. Or an unhealthy round of name-calling.

If one could describe the 10 most important factors affecting the performance of an actual air-pistol in the hand of a real-live shooter, does anybody realistically claim barrel time even makes the cut?

I'll it so simply that.... Barrel time may have a barely measurable effect on grouping, but the DIFFERENCE in barrel time between almost any two air-pistols is deep within the realm of statistical insignificance.

[David M]

Lock time between a FWB 65 (120-130ms) and a EVO (155ms) is significant.
But between PPC guns is negleble.
I would reduce the speed to between 148 -152 ms and enjoy the greater number of shots per tank.
Then worry about what's for dinner....

[brent375hh]

Lock time between a FWB 65 (120-130ms) and a EVO (155ms) is significant.
But between PPC guns is negleble.
I would reduce the speed to between 148 -152 ms and enjoy the greater number of shots per tank.
Then worry about what's for dinner....

David, First off, I highly respect your opinion on this forum. When you say lock time, are you meaning from sear release to pellet has exited the muzzle? If so, do you have a table of these stats?

I still am convinced that it the delta between two guns is more that just the difference in peak velocity, as barrel acceleration is like drag racing. Trap speed and elapsed time can be two different things. Increased striker spring tension also has the be a factor in lock time I think the only way to truly just two guns is high speed photography on the clock.

Lastly, why is 150 meters a second often recommended? If it doesn't matter, why not use 100 and really be frugal with air consumption?

[brent375hh]

Thanks for your post. Of cource, barrel time does mattes. Imagine a lazer beam of zero barrel time....
According to Mr "W" of this forum barrel time does not matter. Howe emptysculled does it get? Just my asking.

Mr. j brent375hh you have just seen the light in practise.

Apparently spell check doesn't work in "old europe" nor, apparently, math or logic. The difference between the specified m.v. of an EVO10 and an LP10 is 37 feet / sec. which represents a 7% change. If the EVO10 barrel time is approximately 2.7 milliseconds, which is close enough for jazz, the lower velocity of the LP10 will increase the barrel time by less than 0.2 milliseconds.

I leave it to the troll who can't get me off his mind to explain how less than 200 freakin' MICROSECONDS makes a practical difference. I suggest it can't be done without invoking the number of angels dancing on the head of a pin. Or an unhealthy round of name-calling.

If one could describe the 10 most important factors affecting the performance of an actual air-pistol in the hand of a real-live shooter, does anybody realistically claim barrel time even makes the cut?

I'll it so simply that.... Barrel time may have a barely measurable effect on grouping, but the DIFFERENCE in barrel time between almost any two air-pistols is deep within the realm of statistical insignificance.

It's odd that the two have different specs. They are virtually the same gun as far as trigger, regulator, firing valve, and barrel are concerned. They can be adjusted to shoot 460-560. Are you calculating barrel time simply by using peak velocity against barrel length?

There is a movement in bullseye away from longslides due to barrel time and follow through by some respectable shooters. I am not arguing, just throwing out my recent perceptions.

[David M]

Locktime for me is the time from sear release to shot clearing the barrel.
If you want to see long, slow locktime try shooting a Flintlock with a poor old flint.
The lock time is long enough to make a coffee.

Back to Airpistol, when testing prior to the 2000 Olympics, doing pellet testing using
a machine rest (both grip mounted and barrel mounted) as well as a chronograph we
came up with some interesting results.

Using a Morini CM 162 electronic starting at 135 m/s and increasing up to 160 m/s.
It was found that the groups were nodal (nearly a sine wave) with the tightest group
at 148 m/s, opening up and the closing back at 156 m/s.
At 148 m/s a three shot group with heavier 0.53g pellets (4.49mm) shot a one hole group,
and you could take a unfired pellet and it would stay suspended in the hole on the target.
The lower velocity also had a better SD and MAD over the chrono.

When hand shot the 148 m/s it felt and scored better that 156 m/s with more feedback.
So I set the pistol to 148 m/s and went off to play the games....

[william]

It's odd that the two have different specs. They are virtually the same gun as far as trigger, regulator, firing valve, and barrel are concerned. They can be adjusted to shoot 460-560. Are you calculating barrel time simply by using peak velocity against barrel length?

There is a movement in bullseye away from longslides due to barrel time and follow through by some respectable shooters. I am not arguing, just throwing out my recent perceptions.

Point 1: No, I did a rough calculation of average velocity over the roughly 10 inches of barrel. I should have made that clear.

Point 2: The various moving parts / moving mass of a recoil-operated centerfire pistol add too many other variables, especially to the shooter's perception of what's happening. Think of the recent thread questioning whether your .22 pistol should or should not lock open after the last round, and then multiply....

[jetpoweredchicken]

As it turns out, the human brain will give "significance" to anything you believe has "significance" and do everything in its power to prove your belief correct. Psychology is significant. Be careful on what you are focused.

[Rover]

While we're on the subject of brains (rather dubious on this forum), let's consider the whole package of meat.

We'll call the whole body/brain reaction time to be around 1/10th of a second. This means that you are
actually shooting in the past. This is the whole reason to just "trust your hold."

A few milliseconds attributed to the gun just doesn't matter. (And you're making Sweet William foam at the mouth.)

[northpaw]

Popular PPC match air rifles have a MV of about 180 m/s.
Maybe the top competitors with those rifles are not aware of the fact that they may get higher scores with a considerably lower velocity, say the above referred MV of 148 m/s ?
Current match PPC rilfes have short barrels, several inches of the front of the "barrel" is simply i shroud, mostly to extend sight radius.One purpose of the short barrel is to reduce barrel time.

[BEA]

I believe I am correct in saying that lock time is related to the speed of the trigger mechanism. This is the amount of time between activating the trigger and when the firing mechanism initiates ignition. Barrel time is different. Generally I think that too much emphasis is put on this issue of velocity. I figure the air pistol manufacturers do enough testing to know where their pistols shoot best in terms of velocity. Most cylinder powered pistols I have had usually go 125 to 150 rds if they start off fully charged. The short cylinder models may be a bit less. Perhaps these new models are different. I shoot an old Morini. As for the length of an air rifle barrel, I suspect the primary reason they are shorter is because once you get to a given length, the expanding gas runs out of energy. Once you get to this point, any additional barrel starts to slow the pellet down. Air rifles may have longer cylinders so this might change the ideal barrel length. I have never seen and air rifle with the barrel extension off, so I do not know what they actual length is. I have had several cylinder powered air pistols over the years. The velocity on all of them has been from about 480 to 525 fps. High speed pellets will go a little faster but I always preferred the standard weight. I could not tell any difference between them other than their balance and trigger characteristics.

[David M]

The real reason most manufactures keep the Airpistols to 150-152 m/s is the legal requirements
around the world.
The Airpistol power level varies from country to country, from 5.7 joules in Canada to 24 joules in Spain.
Most are around the 7.5 j Germany to 8.15 j in England.
So if the pistol comes out of the factory at 150 m/s then they can sell it anywhere.

[brent375hh]

Is it possible that manufacturers only can set up a pistol to shoot it's best out of a machine rest, because it is hard to qualify out of someone's hand?

My pistol was delivered with a perfect hole for 5 shots, but shooting 171 meters per second. Maybe they simply adjusted it until it shot best.

If lock time is unimportant, it seems that makers are always trying to shorten it.

I admit I am far from world class. Shooting a 560 requires my trigger finger to apply more as things look closer, then hold it if they don't, and abort at 8-10 seconds. With limited feedback so far, the higher velocity and quicker striker just seems closer to where the sights where when the sear tripped. I have since dialed it back to 540 fps in an effort to get 100 shots from my 160 bar tank. Maybe when I refill my tank to 200 bar, I will bring it back to the delivery velocity.

[Gwhite]

My understanding is that the manufacturers adjust the velocity (with a specific pellet weight) to be within a certain range known to work well in general (for an example, watch the Steyr velocity adjustment video). They then shoot a test group. If it's good enough, they ship it. If it's off just a little, they may experiment with a different pellet or two, but they don't "tune" each pistol for optimum performance. The pellet weight & size listed on the test target isn't optimized either. It's what they used, and again, if it passes, it ships.

With modern manufacturing methods, they should be able to crank out pistols that will shoot 1 hole groups all day long. Time is money, and fussing with each pistol isn't cost effective. The buyers will typically shoot different pellets anyway, and won't do bench rest testing to confirm the test target performance.

The testing process weeds out the occasional clunker, which may have a bad barrel, regulator or some other mechanical defect. Those get sent back for examination and repair. The quicker they can get the rest out the door, the more money they make.

[brent375hh]

I would assume that they move them along fast too, but was intrigued by the speed of the two Steyrs I bought as opposed to their video on proper speed. No matter how you slice it they are mechanically able to shoot one hole groups all day long. What speed shoots the best out of the hand may be different.

Why I am on the subject, why would people shoot heavier rifle pellets out of a pistol? Even thought the recoil is low, there is some, and I would think that grip pressure would be amplified by the slower, heavier, higher recoiling projectile.

[northpaw]

With limited feedback so far, the higher velocity and quicker striker just seems closer to where the sights where when the sear tripped.

Let me be more specific: The term "barrrel time": The time from the air pressure starts the pellet moving, until it exits the muzzle. Lock time, to me, that is the time from trigger release to air pressure is acting upon pellet,a parameter of receiver of a specific gun.

If shot count would allow a velocity of, say 180 m/s, similar for air match rifles, and recoil absorber was able to handle that,I would go for it. There are some downs: Air has some weight, and, during a 60 shot session and sighters, say 75 shot or so, at 180 m/s (excuse to mr. "W" for me using metric units, hope that may not interfere with his night pleasant dreams) it does change center of gravity during a match. Does that matter? Maybe yes, maybe no.

[william]

If shot count would allow a velocity of, say 180 m/s, similar for air match rifles, and recoil absorber was able to handle that,I would go for it. There are some downs: Air has some weight, and, during a 60 shot session and sighters, say 75 shot or so, at 180 m/s (excuse to mr. "W" for me using metric units, hope that may not interfere with his night pleasant dreams) it does change center of gravity during a match. Does that matter? Maybe yes, maybe no.

Seriously? The ∆ of center of gravity caused by the mass of air lost in a 75± shot match, KEEPING IN MIND THAT IT OCCURS ONE SHOT AT A TIME?

No matter how much he hedges his bet with "Maybe yes, maybe no," the fellow who seems obsessed with me is skating more on the ice of the occult than of the practical. The change in the shooter's blood sugar level over the same time will have much more effect on shot outcome than the nonsense he interjects. What next? The Coriolis Effect? A butterfly flapping its wings over New Zealand? Some other flatus vocis?

[Green_Canoe]

Seriously? The ∆ of center of gravity caused by the mass of air lost in a 75± shot match, KEEPING IN MIND THAT IT OCCURS ONE SHOT AT A TIME?

No matter how much he hedges his bet with "Maybe yes, maybe no," the fellow who seems obsessed with me is skating more on the ice of the occult than of the practical. The change in the shooter's blood sugar level over the same time will have much more effect on shot outcome than the nonsense he interjects. What next? The Coriolis Effect? A butterfly flapping its wings over New Zealand? Some other flatus vocis?

I've been finding the change in my center of gravity due to peristalsis over the course of the match is wreaking havoc with my scores.


;^)