alecto trajectory on 1 & 2 pumps

[pjd-hw100]

Hi all,

I have been trying to work this out using chairgun, fairly sure its to do with flatter.... oh i dont know...

why is the poi lower on two pumps compared to one at the same range. (8m)

I am not changing the zero.

.177 - super domes - holographic sight.

hang on...!!!!... is it because the pellet is on its way down on the first pump and up on the second.....


thanks for any corrections of confirmations...

Pete

[pjd-hw100]

above makes no sense to me now, changed chairgun to 'same angle' for muzzle velocity comparisons and it clearly shows the more pumps the higher the poi should be.

Think i need to check the POI again...

[ikarma70]

its to do with pellet speed and air resistance....faster the pellet, the lower/flatter the trajectory as the pellet cuts through the air easier.

[pjd-hw100]

i know what you mean, however the muzzle angle means that a faster flatter, less resisted pellet ( 2 pumps) should still have a higher POI than the slower, 'loopier?' , slower more resistant pellet??? no???

don't forget i am working at the zero of the lower FPS (1 pump). The initial trajectory cannot get below the starting point of 1 pump. the physics (i think) means the slower pellet gets affected quicker by gravity than the faster pellet and gets pulled down earlier?????

so why the lower poi with more FPS?




i am sure this i simple and i just dont get it.

[Cones]

If the pellet is rising (along the first part of the trajectory curve) then the faster velocity will cause it have a flatter curve.

So it will hit the target at a lower point of impact.

If you shoot at a longer range (on the downward part of the curve) then the POI would drop less with the higher velocity than the lower one at the same distance.

HTH

Mark

[air-tech]

I take it your POI is lower with 2 pumps, in reality, and not as CG suggests? I am not familiar with CG, note.

This would be related to the recoil of the gun but I am surprised you have this effect on a pumper rather than a springer.

The simple answer is that the muzzle has more time to rise prior to pellet departure when on a single pump.

But as above I am surprised somewhat at this behaviour on what is a very low recoil gun. With a springer this is to be expected.

Possibly it's to do with trigger release rather than recoil.

[oliver13]

What Air-Tech said.

What is the size of POI change are you describing anyway?

Do you have some way to clamp the pistol, & see if the effect remains?

Let us know how you get on, these sort of anomalies are always interesting to explore.

Regards

[pjd-hw100]

I am getting a poi drop of 15mm on two pumps at 8m.

I will perform some more test shots when I get time?

Does anyone else with an Alecto get the same? I know my friend who also has one does.

I just don't get how with the same muzzle angle the more powerful (2pump) shot hits lower. Surely it should be higher.