Walther LP500 energy and fps adjustment

[mhayford45]

Does anyone know how to adjust the energy and fps for a LP500? It is not covered in the manuel and I cannot find any online reference materials.

MIne is running about 5.71 Joules with a .53g pellet at ~ 480 fps. This seems a bit low as the specs say 7.5 Joules which should be nearer to 600 fps. Or, is this typical for LP500s?

Thanks for any help
Mark

[william]

1. I don't have the answer you asked for.

B. Unless you're dissatisfied with the way it (not you) groups, don't mess with it.

[atomicgale]

. . . with a .53g pellet at ~ 480 fps. This seems a bit low

Drop the .53g (8.2 grain) rifle pellet & switch to .45g 7.0-grain pistol pellet.

If the accuracy is there, who cares about joules?

[McMadCow]

So I've had to take mine apart for some cosmetic work, and I've run into something like an answer for you. Take off the valve at where the air hookup is. It's the 4 bolts surrounding the air attachment. Pull the whole thing straight out of the frame and look at the back of it. There's a grub screw at the back that is an M5, I believe. That seems to be the air pressure adjustment. I figured this out when I took mine apart and the gun shot super weak when I put it all back together.

Mine works by screwing in that bolt all the way IN until your hex wrench slips and won't turn anymore. It's a hollow screw and there's a post inside the valve, which is why you run out of purchase.

My picture doesn't show it, but it's the screw on the back of the shaft with the two o-rings.

If the accuracy is there, who cares about joules?

If the gun isn't shooting fast enough, it could be more susceptible to vibrations from your hold.

[william]

"If the gun isn't shooting fast enough, it could be more susceptible to vibrations from your hold."

Sorry, wasn't the barrel-time argument put to bed years ago? Approx. 2 milliseconds is of no consequence. Don't take it from me; look up past discussions.

[brent375hh]

Most guns have an adjustment screw on the hammer spring. Regulator adjustment should not be required.

[David M]

Do NOT touch the regulator.
The velocity is adjusted by spring pressure on the hammer.
It is the same as the LP 200,300 & 400.
Retaining collar is held in the frame with two set screws on side of frame, spring adjustment screw is in the centre of collar.
Clockwise increases, anti clockwise decreases.
Use a chronograph and set to between 148 to 155 m/sec.
Remember the higher velocity may not produce any better groups but just uses more air.

[william]

How many groups has the O.P. shot through this pistol? I'm guessing not nearly enough to think of monkeying with any critical adjustment. Given all the great scores registered with SSPs pistols, it's hard to make the point that 480fps poses any sort of handicap. Other than the brainworm, if you've really got it into your head that the velocity is too low.

[atomicgale]

running about 5.71 Joules with a .53g pellet at ~ 480 fps. This seems a bit low

Kinetic energy (joules) = 1/2 * mass(kg) * velocity^2 (meters/second)^2

Solve for KE (joules) = 1/2 * .00053kg * (146.3 m/s)^2
KE = 5.67 joules

1. Keep KE constant
2. Change mass from .53 g to .45g (switch from rifle pellet to pistol pellet)
3. Solve for velocity

KE 5.67joules = 1/2 * .00045kg * (velocity m/s)^2
Velocity = 158.74 meters/second
convert metric to imperial
Velocity = 520 feet per second (OPTIMAL)

Real-world Solution: Don't mess with the pistol

Hope this helps.

[mhayford45]

I did not know if the velocity was low or otherwise. The only information the man gave was 7.5 Joules. Therefore I was asking as the chrono gave me 480 fps with the Eley heavy and 516 fps with RWS R10 Pistol. Then I calculated the energy.

This LP500 groups best with the heavy pellets... not that the the pistol pellets were grouping poorly.

[robjob]

I secure the gun in a vice in my work bench by wrapping towels arround the cylinder and clamping just hard enough so that the gun is firmly held. If it shoots from a firm rest, don't mess with it... velocity doesn't matter, groups do...

And yes, heavy pellets shoot better in almost all guns I've tested...

[Rover]

"And yes, heavy pellets shoot better in almost all guns I've tested..."

Funny, Don Nygord told me it just doesn't matter.

I've made excellent groups with light pellets. I had a 30 shot group with RWS Basics that was barely larger than the "11" ring.

It sounds if your gun is performing exactly as it should.

[McMadCow]

Yeah, my LP500 likes light pellets (7gr Meisterkugeln) just fine.

[northpaw]

2 milliseconds is of no consequence.

If we follow that way of thinking, 3 milliseconds wont be of any consequence, and 4 milliseconds wont, and so on.
At what level does it really start to matter?
Adjust velocity way down to 390 fps, to increase shot mileage?

[masaki]

mhayford45,
>Does anyone know how to adjust the energy and fps for a LP500? It is not covered in the manuel
No, I do not. I do not remember where it was mentioned in the manual, but I clearly remember it was mentioning something like "the velocity has been factory adjusted and do not attempt adjust by yourself."

For your information, the followings are my LP500 muzzle velocity measurement results:

Pellet: H&N Finale Match for Air Pistols, dia.=4.49mm, weight=0.477grams
Ambient Temperature: 21.3C(70.34F)
Observed Muzzle Velocity: 506fps @ air tank pressure 200bar
Observed Muzzle Velocity: 500fps @ air tank pressure 90 to 70bar

Energy in Jouls, in my case at 200bar and 90 to 70bar in the tank, are respectively
> (* .5 .477e-3 (expt (feet-to-meter 506 ) 2))
5.673086

> (* .5 .477e-3 (expt (feet-to-meter 500 ) 2))
5.539345

ciao!
masaki
Tokyo Japan

[David M]

MIne is running about 5.71 Joules with a .53g pellet at ~ 480 fps. This seems a bit low as the specs say 7.5 Joules which should be nearer to 600 fps. Or, is this typical for LP500s?

Just curious about this 7.5 joules.
The manual actually says....
"The LP500 is a 4.5 mm caliber air pistol that can be purchased by anyone over 18 years of age
without a permit. It is for sport shooting at targets in shooting ranges designed and approved for the
purpose. The projectile energy is less than 7.5 J."
The German Air gun laws says...
"In Germany, air guns producing a muzzle energy up to 7.5 joule (J) (5.53 ft·lbf) can be owned by persons from the age of 18 years and freely acquired provided they bear the "F-in-pentagon" mark" that indicates a muzzle energy not exceeding 7.5 J (5.5 ft⋅lbf) kinetic energy."
The 7.5 j is the legal limit not the spec.
Styer, Morini, walther and FWB are typically 480 to 520 fps.

[mhayford45]

Thank you all for your help. I have and understand the information.

[Isi]

Hi guys…sorry to bring this post up again but i need to ask this…

Isnt more speed on the gun supposedly gives more recoil in it? I measured my lp500 yesterday and gave me 149kmh…which is low in comparison with Steyr’s that gives around 155-160….

Also…does anyone knows if it matters that blue angel doesnt have an absorber on it? If it has would it be any better? Thanks

[brent375hh]

150 mps is normal. "149 kph" is slow.
150 +or - is where the vast majority of air pistols shoot. If you Really want to find out, you could try in up and down the range to see if there is a node that works best, but it might gain you 5-10 points per season when all is said and done.

I do like an absorber that is tuned for zero recoil only to make sure my sights don't move in follow through. The fact that Morini doesn't use an absorber has not stopped many great scores with that equipment. I have bypassed mine, and hand held groups did not change size.

[David M]

I can't believe the amount of mis-information and BS that surrounds some shooters and Airpistols.

" Light vs Heavy pellets" - Light pellets have been around since Adam was a boy. Back in the day
pistols were either spring guns, pump guns or CO2.
They typically ran about 130-135m/s and NEED the lighter pellet. Also the diameter was critical
either 4.48, 4.49, 4.50 to performance.

Now to present day and PCP pistols, these have no power problem, so no problem with weight.
Also most have a loading rod system and size pellets on loading.
The pistols have a regulator to control the pre-charge chamber and a spring to control the valve
opening and timing. The spring is adjustable for small variations with regulator change for major
changes (alter the spring pile).
Example
Styer single shots pistols are typical 6J, the LP50 Rapid 7.5j and the High Power either 12/14J.

Typical PCP Airpistols run between 145m/s to 160m/s, with most around 150-155 m/s.
Most Airpistol groups are sub X ring and unless you are shooting 570 plus, pellet testing is a
waist of time.