Not mechanically inclined.
Does decrease velocity, let say from 515 down to 475, save gas?
Does it give you more shots per cylinder filling?
Or does the pistol regulator gives out same amount of pressure gas, and that downward adjustment in velocity just waste gas without giving me more shots?
Does decrease velocity save gas?
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Re: Does decrease velocity save gas?
Angels dancing on the head of a pin.
Last edited by william on Tue Feb 11, 2020 12:05 pm, edited 1 time in total.
Re: Does decrease velocity save gas?
Does it REALLY save gas?
Does it really lose precision? I have shot in 350 FPS, and as long as follow through hold is good, it is still a tack driver.
But I am more interested in first question, does it save gas? And if yes, how much ? 515 down to 465 would save 10% more gas?
My gut is thinking no gas saved at all.
Does it really lose precision? I have shot in 350 FPS, and as long as follow through hold is good, it is still a tack driver.
But I am more interested in first question, does it save gas? And if yes, how much ? 515 down to 465 would save 10% more gas?
My gut is thinking no gas saved at all.
Re: Does decrease velocity save gas?
Yes, slowing the pellet down saves gas.
Velocity is adjusted by spring pressure on the hammer against the poppet valve.
The harder the strike, the longer the opening time, the bigger the gas volume, the faster the shot.
A 10% increase might require 30% more gas.
The minium velocity is around 350 fps but most are 450 to 550 fps.
My own testing found that accuracy was nodal as the speed increased.
The best group at the least velocity was around 485 fps, then again at 515 and 535 fps.
You need to test your own pistol to see the results.
Velocity is adjusted by spring pressure on the hammer against the poppet valve.
The harder the strike, the longer the opening time, the bigger the gas volume, the faster the shot.
A 10% increase might require 30% more gas.
The minium velocity is around 350 fps but most are 450 to 550 fps.
My own testing found that accuracy was nodal as the speed increased.
The best group at the least velocity was around 485 fps, then again at 515 and 535 fps.
You need to test your own pistol to see the results.
Re: Does decrease velocity save gas?
In regulated airguns, decreasing pellet velocity by simply reducing the hammer spring preload may save gas in total but doing so can cause other problems if taken to far. Bob Sterne on the Gateway to Airguns forums explains tuning a regulated airgun really well in this thread: https://www.gatewaytoairguns.org/GTA/in ... 19.0;nowap
Turning hammer spring preload down to far can result in reduced efficiency, greater shot to shot variability and inconsistent velocity across the pressure range. See the grey line in the second chart of the first post of the thread.
I made a regulated .177 Crosman Maurauder with a carbine length Lothar barrel and lightened hammer and went through tuning it to shoot 10.5gr .177 pellets at 850fps. I tuned for the 'knee' as Bob writes about such that across the pressure range i had minimal shot to shot variability, near max efficiency and a flat velocity trend. It was pretty fun project that consumed lots of pellets.
Precision airgun makers will have likely designed and tuned our pistols to shoot right around the 'knee'. So adjustments are best made while using a chronograph and testing the result across the pressure range. To not waste pellets, shoot maybe 5 pellets every 20 bar from max fill to end of the green zone on the gauge and maybe further to actually establish where the end of the green zone is.
Turning hammer spring preload down to far can result in reduced efficiency, greater shot to shot variability and inconsistent velocity across the pressure range. See the grey line in the second chart of the first post of the thread.
I made a regulated .177 Crosman Maurauder with a carbine length Lothar barrel and lightened hammer and went through tuning it to shoot 10.5gr .177 pellets at 850fps. I tuned for the 'knee' as Bob writes about such that across the pressure range i had minimal shot to shot variability, near max efficiency and a flat velocity trend. It was pretty fun project that consumed lots of pellets.
Precision airgun makers will have likely designed and tuned our pistols to shoot right around the 'knee'. So adjustments are best made while using a chronograph and testing the result across the pressure range. To not waste pellets, shoot maybe 5 pellets every 20 bar from max fill to end of the green zone on the gauge and maybe further to actually establish where the end of the green zone is.
Re: Does decrease velocity save gas?
I set my lp10 at 130m/s with rws r10 and got 220 shots per fill, but you need to adjust the absorber sistem and the holes will be tearings.
5 shot group test = 7mm
5 shot group test = 7mm
Re: Does decrease velocity save gas?
My Combro Mk4 chronograph got rusted, died. Can’t measure velocity now.
At what velocity does paper hole start tearing a bit? 400 FPS? Must be much more quiet at that puff speed.
At what velocity does paper hole start tearing a bit? 400 FPS? Must be much more quiet at that puff speed.