AA S200 Bells & Whistles - Poor Results

[rabbitslayer]

There are those on here that know a lot more about this than me and it is a long time since i went into a s200. my thoughts are that normally with a 180 bar fill that pressure is being overcome by a strong firing valve spring sealing the firing valve, now the reg is there and the pressure delivered to the firing valve is 95 bar then the firing valve spring is too strong and the hammer spring is working too hard to overcome that tension. When i set up a Steyr it's about the balance of reg pressure vs firing valve spring vs hammer spring, i think that's your problem. see if you can find a 'softer' hammer spring or contact the reg supplier as he must have had this question before?

Thanks ChrisC.

I understand the aim here now. The trick however must be knowing how to interpret results in relation to adjustments made and thats where my inexperience lets me down.

Wouldn't it be possible for suppliers to offer balanced firing valve and hammer springs matched to the pressure setting of the regulator they sell? Would be too easy I suppose

[GB2017]

on a slight cautionary tangent, have you tried chrono'ing with another pellet?

reason I ask, is that from my understanding of some previous threads superfields can measure low on a chrono, meaning that if you try with jsb's and their ilk you will measure substantially over, you might decide to wind the power down a tad

[rabbitslayer]

on a slight cautionary tangent, have you tried chrono'ing with another pellet?

reason I ask, is that from my understanding of some previous threads superfields can measure low on a chrono, meaning that if you try with jsb's and their ilk you will measure substantially over, you might decide to wind the power down a tad

Thanks for this info.. Not tested with anything other than Superfields at the moment. Only reason I went for these is that the previous owner said the gun preferred them. I have got AA fields, JSB exacts and Soverieign Rangemasters waiting in the wings. I'll look at trying these out later but for now I'd like to concentrate on improving the shot count and consistency. Once I'm there or thereabouts I'll go onto the other pellet types and check power is below FAC.

John.

[ChrisC]

Thanks ChrisC.

I understand the aim here now. The trick however must be knowing how to interpret results in relation to adjustments made and thats where my inexperience lets me down.

Wouldn't it be possible for suppliers to offer balanced firing valve and hammer springs matched to the pressure setting of the regulator they sell? Would be too easy I suppose

Yes mate, you'd have thought that the reg supplier (if they had been contacted about this before) would have put together a small kit to make it an easy, DIY job. I mean, they must have experimented with the settings before making a product to sell?

To revert back to Steyrs. The newer models had an external power adjuster that meant an allen key could be used to push the power above the limit. Steyr in thier wisdom introduced a transfer port with a reduced diameter. the problem was that the shot count almost halved with the (silver) port fitted and the firing valve spring,reg and hammer spring were out of balance. The hammer spring had to be wound right in to get the power to a useable level which meant that the hammer smashed into the friing valve which in turn bounced. The result was a much lower shot count, harsher firing cycle and a vastly reduced life for the internals.....not a clever solution.

I suspect that you've got something similar going on but i also think it should be an easy enough fix......someone on here (or the reg supplier) will have just the info you need....hopefully.

[rabbitslayer]

IMPROVEMENT!.. but not there yet

After some helpful replies, info and advice from you guys today I went ahead with reducing the hammer spring tension. I wound the adjuster all the way out until the face was level with the breach block. Result as per below.

Air Arms S200 - .177
RWS Superfields - .177 8.4 Gn
Shot No: FPS Ft/Lb Pressure Check
1 782 11.42 190
2 784 11.49
3 786 11.53
4 780 11.35
5 780 11.35
6 781 11.39
7 785 11.51 180
8 785 11.51
9 784 11.46
10 791 11.67
11 784 11.46
12 785 11.51
13 790 11.65
14 790 11.65 170
15 793 11.75
16 788 11.60
17 791 11.67
18 786 11.83
19 790 11.65
20 788 11.58
21 788 11.58 160
22 789 11.63
23 791 11.67
24 786 11.53
25 788 11.60
26 788 11.60
27 782 11.42
28 784 11.49 150
29 790 11.65
30 784 11.49
31 786 11.53
32 790 11.65
33 788 11.58
34 791 11.67
35 788 11.60 140
36 786 11.53
37 781 11.39
38 784 11.49
39 781 11.39
40 783 11.44
41 784 11.46
42 785 11.51 130
43 788 11.58
44 782 11.42
45 785 11.51
46 785 11.51
47 789 11.63
48 789 11.63
49 787 11.56 120
50 789 11.63
51 788 11.58
52 789 11.63
53 789 11.63
54 790 11.65
55 795 11.79
56 792 11.72 110
57 792 11.72
58 794 11.77
59 790 11.65
60 787 11.56
61 790 11.65 100

What should I do next as shot count still not as high as I expected (60 fish total). Should I increase the firing valve spring tension slightly and should this then reduce air usage / increase shot count? Or.. do I start looking for a shorter than standard hammer spring? OR... is it 'suck it and see'

I'm also a little worried about power spikes especially when you look at those recordd at 110 bar and below. What is this telling me? power creeps up the closer the internal air pressure is to the regulator pressure setting?

All comments / advice will be gratefully received.

John

PS.

Sorry for the jumbled up data. There doesn't seem to be a way of importing / inserting a table.

[bezzer]

The "spike" at 110 bar is when it's coming off the reg , the gun settings you've got at the moment are working at their most efficient meanjng the reg is set a touch too high you get a few higher power shots then it drops right off.
Turn it down just a very small amount then do another string and see what that gives you. When you get a flat string you're at optimum reg pressure then you can start altering the other bits to get the power you want from that reg pressure

[rabbitslayer]

The "spike" at 110 bar is when it's coming off the reg

Don't understand what 'off the regulator' means.

The gun settings you've got at the moment are working at their most efficient meanjng the reg is set a touch too high you get a few higher power shots then it drops right off.

Do you mean the reg is currently set higher than 95 bar (indicated on the reg body), and is closer to 110 bar?

Turn it down just a very small amount then do another string and see what that gives you. When you get a flat string you're at optimum reg pressure then you can start altering the other bits to get the power you want from that reg pressure

What do you mean by a flat string... same FPS, no variation throughout the complete no' of test shots? Sorry if I seem thick

I was hoping I wouldn't have to touch the reg again. It's an internal reg and I hate pushing it past the internal cylinder threads. It's quite hard to push it past the threads and it feels like you're going to knacker the outer body 'o' ring on the reg. Ah well if needs must

[bezzer]

Falling off the reg means the main cylinder pressure has gone below the reg pressure so you're getting air at the same pressure either side of the reg i.e. the pressure has dropped below 95 bar and working as if the there is no reg there.

flat string = a string of similar velocities like you have been getting but that doesn't spike at the end just drops down.

Missed the fact it should be 95bar which is on the low side anyway for a .177, ignore me saying turn it down you can also eliminate the spike with the other settings, to save a load of typing and will be a lot clearer watch Rob Lane's video on what to do.https://www.youtube.com/watch?v=4gBFdY3YDxc

[rabbitslayer]

Falling off the reg means the main cylinder pressure has gone below the reg pressure so you're getting air at the same pressure either side of the reg i.e. the pressure has dropped below 95 bar and working as if the there is no reg there.

OK - I get that.

Flat string = a string of similar velocities like you have been getting but that doesn't spike at the end just drops down.

OK

Missed the fact it should be 95bar which is on the low side anyway for a .177, ignore me saying turn it down you can also eliminate the spike with the other settings, to save a load of typing and will be a lot clearer watch Rob Lane's video on what to do.https://www.youtube.com/watch?v=4gBFdY3YDxc

OK.

Going back to the reg setting. If it's falling off the reg at 110 bar, then this means the reg must be set at around 110 also and not at 95 bar? (sorry to repeat the question).

I'll watch the vid now.

Thanks for your help bezzer.

[Geoff555]

OK spring length. ( new genuine.).
44.35mm.
1.746".
Cheers.
Geoff.

[garym]

Following this with interest. Thanks guys.
I have a similar issue after fitting a Altoros reg to my cz 200.
Altoros advice me to adjust the 'striker spring' to the minimus. I assume they mean the hammer spring.
If I can get 60 shots and a plateau as above I will be very happy.
Cheers G

[rabbitslayer]

Altoros advice me to adjust the 'striker spring' to the minimus. I assume they mean the hammer spring.

Yes, Hammer spring.

[rabbitslayer]

OK spring length. ( new genuine.).
44.35mm.
1.746".
Cheers.
Geoff.

I haven't got my 'verynears' () handy but using a tape measure it looks like it bang on 45mm.

[rabbitslayer]

Isn't decreasing tension on the hammer spring the same as increasing firing valve spring tension? Doesn't it have the same effect?

[garym]

I thought the same, but happy to be enlightened.
Good thread guys.