Shot string deviation.

[Sake-san]

Is that with calibrated (weighed) pellets or just "out of the tin?"

[Longshot]

unsorted id guess , that's they way ill go as I am a hunter . I would be happy with any gain on air as well as smoothing out the variation

[Longshot]

Had a rare day off today so set about the project , gun as received by a FTF deal looks good and well kept , Running hot though so stripped & adjusted firing pot to tap it down . once tapped to 55 it was way under so happy that all was well with ports & springs then fitted the reg . Now all i can say is 40 shots within 10 fps & some sort of flat line on the graph said it's working , cant qoute no's but now needs adjusting . Q is who has had to go down this path & what to do ? still waiting for a reply from Alteros

[Longshot]

Have stripped the s410 now ready for service , findings so far are she was running hot peaking at a shade under 14 . The venturi screw made no difference not even the new one .
As Delivered @ 58.5 mm

My thanks to Julian who has given me Advice & supplied parts for the service



After adjusting to 55mm power went way down



Happy that all was well I fitted the reg as supplied running hot again



After adjusting to the settting shown on the Alteros site for 100 bar , we are nearly there might have to bring it down another tad Still a little disappointed with the shot count at this point , so hammer bounce might be wasting some air.

[Raj]

You can comfortably fill to 200 bar now you have regged it. You will find that you are adding another 25 shots in front of that last graph at a consistent power level, the same as your first 40 shots currently shown.
What is your venturi doing at this point? It should be nearly doing nothing. Key is to set it up to give you a peak of say 11.6 ft.lbs with the main spring, then use the venturi to bring it down to 11.4 ft.lbs. Maximum shot count, minimum air choked back by the venturi.

[Longshot]

You can comfortably fill to 200 bar now you have regged it. You will find that you are adding another 25 shots in front of that last graph at a consistent power level, the same as your first 40 shots currently shown.
What is your venturi doing at this point? It should be nearly doing nothing. Key is to set it up to give you a peak of say 11.6 ft.lbs with the main spring, then use the venturi to bring it down to 11.4 ft.lbs. Maximum shot count, minimum air choked back by the venturi.

Raj running low on air now only got 180 ish in tank , the venturi is all the way out any adjustments done via the reg , hammer spring & everything else STD .I would like to turn the reg down a little bit more to see if the spread get's worse as the setting goes down further . TBH i was hoping to save air not add more but I have a pal with 300 bar so ill check that out next.

[Mark112]

Hi,

Are you sure you have been adjusting the venturi screw? The venturi screw is the 1.5mm Allen headed screw hidden underneath the cap that you can see on the outside of the gun. You may find that it has to be wound in a long way before any effect is noticed though.

Mark

[32:1]

Have you tried hammer springs and the valve spring too, both these are really what your trying to balance, I found with greater valve spring pressure, stock porting and no port screw along with a softer hammer spring gave me better shot count and a nice curve, that said Ive been fitting Lane regs to all me AA's as their so effective. Reg pressure is only one part of the job !

[32:1]

Had a rare day off today so set about the project , gun as received by a FTF deal looks good and well kept , Running hot though so stripped & adjusted firing pot to tap it down . once tapped to 55 it was way under so happy that all was well with ports & springs then fitted the reg . Now all i can say is 40 shots within 10 fps & some sort of flat line on the graph said it's working , cant qoute no's but now needs adjusting . Q is who has had to go down this path & what to do ? still waiting for a reply from Alteros

What fps are you getting, as 40 shots seems low. Is gun running hot ?

[Raj]

the venturi is all the way out any adjustments done via the reg ....

Dont ask me why but this causes a bit of an erratic result. In my experience, winding the venturi in ever so slightly from the fully open position (by about 10 feet/sec) has a calming effect on the power graph. So for example, with AA Diabolos 8.4grns pellets, you might want to set the pellet speed at 790 FPS with the hammer spring and then wind it down to 780 FPS with the venturi.