The air consumption of the Steyr LP10

[Rover]

I still say he F'ed up by not buying a piece of equipment he could handle....SSP.

[SamEEE]

I still say he F'ed up by not buying a piece of equipment he could handle....SSP.

ಠ_ಠ.

A drop of Cyanoacrylate should do the trick to turn the absorber 'off'. :D

[Rover]

Another guy with simple, elegant solutions!

[David W. Johnson]

Thanks to J-Team for the very helpful illustration.

LP-@ with Steyr 200 bar cylinder hit 130 shots tonight with a sliver of green between the needle and yellow. I presume the yellow / green line is 60 bar?

[J R]

According to a service report, output pressure of the regulator in my LP10E is 70 bar and muzzle velocity is around 165m/s with 0.53g pellet.
One full cylinder is good for at least 100 shots.

[rmca]

According to a service report, output pressure of the regulator in my LP10E is 70 bar and muzzle velocity is around 165m/s with 0.53g pellet.
One full cylinder is good for at least 100 shots.

That is a little to high. With lighter pellets (0.45g RWS Basic for example) you should be getting around 175m/s
Turn it down to 150m/s to 155m/s using those 0.53g pellets. It should give you another additional 15 to 20 shots.

155m/s is the recommended factory speed.

Hope this helps

[northpaw]

Both Pardinis would get amost double the amount of shots per cylinder than the Steyrs. Although the Pardini does have a physically larger cylinder, I think that they Steyr is simply an air hungry design.

Yes, it is. (Some individual is apparently trying to put a smokescreen over this fact....)

I would not be confident firing more than about 100 shots from a completely full LP10 cylinder, and would definately top up between match and final.

Agree.
From your picture of the test target, I noted: from full cylinder your point of impact relative to that of 60 bars, there is a substantial vertical drop. If your pistol was regulated to hit dead center from full cylinder, your impact point at 60 bars would be about a low 8 at the standard ISSF 10 m target. Question is, at which pressuse does the drop of impact point start? My LP 10 start to lower its impact point from about 85 -90 bars (estimated from pressure gauge pointer).

Thanks to those of you who have deared to verify the truth about the unusual hight air hunger of the LP10. Some others are, suprisingly to me, willing to shout very loud to deny this fact.

And, to those repeatedly contradicting fundamental laws of physics: an air pistol with a vented barrel does consume more air to reach a given velocity, relative to a similar unvented version. Period. (The barrel of a LP10 has more vents.)
Hope this helps.

[rmca]

Thanks to those of you who have deared to verify the truth about the unusual hight air hunger of the LP10. Some others are, suprisingly to me, willing to shout very loud to deny this fact.

And, to those repeatedly contradicting fundamental laws of physics: an air pistol with a vented barrel does consume more air to reach a given velocity, relative to a similar unvented version. Period. (The barrel of a LP10 has more vents.)
Hope this helps.

Stop behaving like a spoiled brat who's toy isn't working properly!
If you want to challenge or refute any of my arguments do so like a man. Don't use childish innuendos!

1- Yes, there are other pistols that can do more shoots per cylinder. I never refuted that. The pardini has a larger tank and holds 250 bar of pressure, so no wonder it can do more shots. Other brands may use less air, but they also recoil more (morini for example).

2- Saying that a pistol that can do twice the shots needed to compete is hardly a "unusual hight air hunger of the LP10". When it reaches 100 bar, replace the cylinder with a full one or fill the cylinder. If you want a pistol that doesn't need to change cylinders, take Rover's advice and get a SSP! They are just as accurate. And cheaper!
If you're good enough to reach a final, just replace or fill the cylinder in the mean time... It's what I do!

3- The laws of physics... Where should I start... By the time the pellet (that acts like a seal) reaches the first port on the barrel, the volume of space available to the pressure has increased quite a lot. It went from the small space above the trigger plus the space in the bolt, to that same area plus the space in the barrel. That's more than double, which means less than half the pressure acting on the pellet. By that time, the valve is already closed (way before by the way). So no more air escapes due to the ports on the barrel. I thought I'd made that clear before...

4- If you chose to believe any of what I wrote or not, I simply don't give a damn. But don't call me a liar.
Refute what you want in a decent manner and I will discuss it back, like a civilized person.
Act like a child and I will simply ignore you.

And I REALLY hope this helps (no sarcasm!)

[micken]

4- If you chose to believe any of what I wrote or not, I simply don't give a damn. But don't call me a liar.
Refute what you want in a decent manner and I will discuss it back, like a civilized person.
Act like a child and I will simply ignore you.

And I REALLY hope this helps (no sarcasm!)

I think you've hit the nail on the head here.

northpaw mis-quoted my first contribution on this thread and accused me of exaggerating. I pointed this out for his information but he's not made any further comment.

We could get into physics but maybe we ought to start a new thread and leave the sandpit. :-)

[j-team]

Well...

My final suggestion is that you all put your LP10s (or any PCP pistol for that matter) in a machine rest with a full cylinder and shoot 10 shot groups untill it's empty. Then you will know how many shots you can fire before things start to change and at what pressure reading that starts to happen. Not theory, but actual facts.

[therider]

3- The laws of physics... Where should I start... By the time the pellet (that acts like a seal) reaches the first port on the barrel, the volume of space available to the pressure has increased quite a lot. It went from the small space above the trigger plus the space in the bolt, to that same area plus the space in the barrel. That's more than double, which means less than half the pressure acting on the pellet. By that time, the valve is already closed (way before by the way). So no more air escapes due to the ports on the barrel. I thought I'd made that clear before...

rmca, there is something I dont'understand of your statement.

I always believed that the moment you load the pistol, air moves from the cilinder to a small chamber. Afterwards I thought the valve is closed and when you shoot only the air in the small chamber propells the diablo.
Am I wrong?
If what I wrote is correct, it does not matter weather the barrel has vents or not.

Can anybody comment on this please?

[j-team]

I always believed that the moment you load the pistol, air moves from the cilinder to a small chamber. Afterwards I thought the valve is closed and when you shoot only the air in the small chamber propells the diablo.
Am I wrong?
If what I wrote is correct, it does not matter weather the barrel has vents or not.

Can anybody comment on this please?

No. The only thing that happens when you cock the pistol is that you pull back the striker which when released, hits the valve stem releasing air. The amount it releases depends on the strength of the spring, the weight of the striker and also the size (surface area) of the valve (as it will be partially pushed back closed by air pressure). The regulator allows the "smaller chamber" to fill with lower pressure air as long as the pressure difference allows, so as soon as you fire a shot this chamber will immediately recharge. Pressure regulators work by having a larger piston on the low pressure size and a smaller on on the high presure side. The low pressure acting on a larger piston can overcome the high pressure acting on a small piston therefore closing off when the pre-set pressure is reached. The amount of pressure it regulates is determined by the spring force in the regulator, which in the case of a Steyr is a stack of spring washers (also known as bellevue washers).

[rmca]

rmca, there is something I dont'understand of your statement.

I always believed that the moment you load the pistol, air moves from the cilinder to a small chamber. Afterwards I thought the valve is closed and when you shoot only the air in the small chamber propells the diablo.
Am I wrong?
If what I wrote is correct, it does not matter weather the barrel has vents or not.

Can anybody comment on this please?

Pardini guns (at least the k10) uses that small "in between" chamber. That is why when you unscrew the cylinder you still have air for one more shot.
Steyr LP10 doesn't work like that. The valve sits right after the pressure reducing valve. See the picture below. You can see the end of the valve in yellow, and a small chamber thats connect to the hole you see when you open the bolt. There is no way possibility of air being trapped there as it's always open (it leads to the barrel). So when you unscrew a cylinder in a LP10 you release the air thats in the pressure reducing valve (as do most guns), but there is no more air trapped inside the pistol.

Hope this helps

[David W. Johnson]

Thanks to J-Team for the very helpful illustration.

LP-@ with Steyr 200 bar cylinder hit 130 shots tonight with a sliver of green between the needle and yellow. I presume the yellow / green line is 60 bar?

I fired another 10 from the same cylinder just for fun. They were all low. I think 130 is the outer limit for mine. As I get better, that line might move.

David

[therider]

Thanks j-team and rmca for your detailed explanations.

I think that my MGH1 also works as the pardini. I saw the video in YouTube release by Cesare. You load a chamber behind the diabolo when you cock and this is released to propel.

Is this the reason why the velocity of my Mgh1 is so consistent and the air consumption is so little,despite having a velocity of 172m/s (until last week it was 175-176 m/s)?????

[flolo]

maybe, it's always about how consistent the pressure regulator works, depending on it's design

@therider: thx alot for you know what. i'll contact you in the next days

[northpaw]

Is this the reason why the velocity of my Mgh1 is so consistent and the air consumption is so little,despite having a velocity of 172m/s (until last week it was 175-176 m/s)

Regrettably, I don`t own a Mgh1 myself, but does that gun feature a vented barrel? If not, I may understand your increased shot count pr. cylinder.

It comes as å surprize to me that some individuals of this forum does not, intuitively, understand that a vented barrel consumes more air than an unvented barrel to achieve a given muzzle velocity.
Let us put it simple: imagine we just drill some more holes in the barel of a LP 10, say add same number of holes, same diameter, same distance from breach. Will the added holes reduce velocity for a given amount of air released behind pellet at discharge? Or will velocity stay uninfluenced by the added vents? Those who vote for stable muzzle velocity dispite the added ventholes may now raise their hands.
Got it?
Hope that helped some. :-)

Let us summarize: the LP 10 is an airhungry construction, in my experience, considerably more so than similar guns, for å given, relatively high, muzzle velocity in the 155 - 160 m/s ballpark.
Steyr had better reconstruct the internals of the gun, and/or increase air-cylinder volume, - make å larger cylinder that is.

To those who claim they have a mileage of 130 or more "full Power" shots from one cylindre: that is simply not possible, given he small volume of the air cylinder of an LP 10. Your "full Power" setting is then way below the factory recommended "close to 160 m/s".
We find it a bit strange, given the recommended velocity from owners maunual, that all of the LP10s I have seen in our club, have all arrived with a factory velocity setting much blow the 160 m /s, actually closer to 140 m/s.

130 "full Power" shots from one cylinder? That "full Power" is simply less than 155 - 160 m/s. Get a chronograph and confirm this yourself.

[rmca]

Of course the barrel vents will decrease the pressure, but that's not the point! The valve is well closed by the time the pressure gets to the pellet.
So, even if you stick the absorber in place, or plug the holes, your air consumption will not change! You might get a small increase in speed, emphasis on "small", but your problem still remains.

As I said, there is something wrong with the gun (or guns?), so if I was in your shoes I would send it to an authorized dealer or to the factory, whatever was cheaper.

Hope this helps

Hope this helps

[therider]

Northpaw analysis of the effect of the vents on muzzle speed is correct.
You can have a look at this
http://www.kiledjian.elac.org/phys%2000 ... %20Gun.pdf

Are the vents really necessary? I have not found any evidence of their usefulness. Any suggestion?

[RobStubbs]

I've read most of the above thread, but I can't say all of it. I would state that you will get far worse precision and acuracy from your gun with the absorber off. It's not a case of making it like an LP2, it behaves differently. Mine broke a couple of years back and it became unusable. From shooting 9's and 10's the groups opened out to 7's and 8's so group size became about 3 times larger. I got it repaired and back to where it was before. If you are getting through lots of air, then look for a solution to that problem - i.e. something maybe leaking - rather than trying to muddle through it with a sledgehammer approach.

Rob.