S200 string

[Geordie]

You guys sure know your stuff Its all Greek to me

[GrandadG]

You guys sure know your stuff Its all Greek to me

I'm with you Geo....i was reading the last few posts and something went "twang" between my ears
made a mental note....... "do not try this yourself"

[singlespeed]

You guys sure know your stuff Its all Greek to me

I'm with you Geo....i was reading the last few posts and something went "twang" between my ears
made a mental note....... "do not try this yourself"

If your familiar with finding the sweet spot for a fill, you will have seen the graphs rising up to 160bar then dropping off untill 110bar then a sharp drop off. Setting up to run at lower pressures gives a much tighter sweet spot.

Ideally the regulator would be set to control at the point where the port and valving etc is most efficient... operating in the sweet spot or the point where the peak of the speed occurs, which is a small hump on this graph which corresponds with about 115bar air pressure.

Here, at pressures below 115bar the power starts to drop off gradually then quickly just like an unregulated rifle.
Just like a unregulated rifle, filling pressures greater than the sweet spot sees a drop in power/pelet velocity. However the regulator stops the drop off effect as the regulator starts to control the pressure so you get a flat line from here up to your maximum fill pressure. (or at least you should get a flat line.)

Reduccing the regulator pressure should see a graph like
__________________
. . . . . . . . . . . . . . . . \

Instead of
_____________/\
. . . . . . . . . . . . . \

[Dan]

I'm with you two . As much as I appreciate the advice and I really really do,I don't understand any of it I wouldn't know where to start . I just wanted to know if it was OK I'm not looking for amazing because it's much better than it was pre regulator .I wanted more shots and it's achieved that and actually exceed my expectations . Like I say when I see those numbers it means nothing to me I just wanted to know if it was a half decent spread ???
But if anyone wants to come round and try to improve it the tea and foods on me
Thanks again guys I appreciate all the feedback and advice.

[Dan]

If your familiar with finding the sweet spot for a fill, you will have seen the graphs rising up to 160bar then dropping off untill 110bar then a sharp drop off. Setting up to run at lower pressures gives a much tighter sweet spot.

Ideally the regulator would be set to control at the point where the port and valving etc is most efficient... operating in the sweet spot or the point where the peak of the speed occurs, which is a small hump on this graph which corresponds with about 115bar air pressure.

Here, at pressures below 115bar the power starts to drop off gradually then quickly just like an unregulated rifle.
Just like a unregulated rifle, filling pressures greater than the sweet spot sees a drop in power/pelet velocity. However the regulator stops the drop off effect as the regulator starts to control the pressure so you get a flat line from here up to your maximum fill pressure. (or at least you should get a flat line.)

Reduccing the regulator pressure should see a graph like
__________________
. \

Instead of
_____________/\
. \[/quote]


This makes a bit more sense to be honest ,but I personally would touch it as I'm really bad with things like this.

[singlespeed]

This makes a bit more sense to be honest ,but I personally would touch it as I'm really bad with things like this.

If the power is still safely legal at the spike after the regulator has cut out then you could live with it. However do some testing with several heavy pellets at the spike area to comfirm as some pellets are much more efficient than others.

If the spike is close to or above 11.5ftlb, theres not much leway on being legal (the string showed 710fps at 10.4 grain which is 11.64fpe). The previous 70 shots being safely under 12fpe wouldn't be a case if a few shots go over it. Being as ive also seen bisley magnums quoted as 10.6gn you could be at 11.87fpe at the moment and there may be some more efficient pellets about.

Screwing in the restrictor screw (clockwise) 1/8 or 1/4 turn will reduce the power overall and being as its making the transfer port smaller it will also move the spike to the left, so it may well end up in the regulated area.

[Dan]

Very interesting stuff and very well explained . When you say restrictor screw do you mean on the reg it's self or on the rifle ?

[singlespeed]

Very interesting stuff and very well explained . When you say restrictor screw do you mean on the reg it's self or on the rifle ?

https://youtu.be/yhsC6yMuPB4 shows the fitting of a Huma reg to an S200.
I was meaning the restrictor (venturi adjuster) on the rifle which is shown at 10:18 as this would reduce the power and by restricting the port slightly more, a byproduct is the spike should occur at a slightly higher pressure.

Although if your restrictor still has AT fitted, the S200 has relatively easy adjustment of the hammer spring tension so you could back that off slightly to reduce the power to be safely under the 12fpe limit.

4:40 shows the regulator and you can see the brass section with a slot cut in it, which could be adjusted (screwed clockwise) to reduce the regulated pressure... this would actually increase the power output when the regulator is controlling the pressure, upto the point where the spike previously occured, so effectively so there's no spike. Followed by reducing hammer spring tension to bring everything down again.
http://huma-air.com/we-added-a-pressure-scale-on-our-regulators/

[Dan]

Oh I see what your saying I have mine turned right down and I use the hammer spring to adjust the power . That's how Raj set it up I think .