AA S200 Bells & Whistles - Poor Results

[bezzer]

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

Only problem is every gun even the same model can be slightly different. 400-500 users have it easier as if you're prepared to pay his price TR Robb sells a set a different hammer springs for them that you can experiment with. I managed to get set cheap off here a while ago which helped a lot but I did make some lighter, longer stroke hammers and different thickness spring preload spacers as well to mix and match until I got the optimum set-up. You could do worse than by checking Rob Lane's regulator YouTube videos there's one for every circumstance/problem. Not specific to the 200 but the principles are the same for every make of reg.

[Geoff555]

Hello, well here we go. I have A200 in both .177 and .22 . Now which reg have you fitted, the internal one or there is an external one. The external one requires No hole or anything, 'O' rings and end cap done up tight. The internal one not sure about because I haven't used them. The firing valve all the way in and back out 1 turn is a good starting point. The striker ( hammer) screw was set flush with the end of the breach block on the .177 this worked out at 11.4 ft-lbs. On the .22 I could not get it above 10.4 even with the adjustment screw turned in almost to the point of not being able to cock it. Cleaned, polished everything etc. made no difference. The spring had gone weak and was shorter than a new one by a good 3/16". A new spring cured the problem. On both the reg. was set to 95 bar. The transfer port screw was all the way out on both. Air used about 1 bar per pellet so a good 90 shots and if you compensate for a bit of 'loss' then usable down to 75 bar.
If you are prepared to have a bit of a twiddle and not hurry then all comes good.
Best of luck.
Geoff.

[air-tech]

I am no expert in setting PCPs up so bear in mind.

But as ChrisC said a softer hammer spring may be in order, and, assuming this is doable for this gun and you have a spare, shortening the valve stem is another option to prevent it opening too far.

[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.

[rabbitslayer]

It's a pain having to empty and refill each time but if you put a piece of brush handle or similar in the reservoir at least you won't be using/wasting as much air each time you alter it. I used a piece of nylon bar in mine.

That's a good idea. Didn't think of that at all... Thanks

[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.

[bezzer]

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).

Would appear so if your gauge is accurate, but the last overall string you posted isn't that bad really, you should get away with not having to mess with it just the other stuff - springs and hammer so you're using less air and getting an increased count.

[Geoff555]

Hello back again. I didn't want to complicate matters so I left this out.
On the .22 then having the screw flush with the breech block was too much and it was wound out about 1/8" further. I was not comfortable with this so I got a gas torch out , got 1 coil red hot and collapsed it. Screw is now flush with the breach block.
How old is the spring just as a matter of interest? Later I will measure a new one and come back with the length so you can compare it with what you have got .
ATB.
Geoff.

[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]

Hello back again. I didn't want to complicate matters so I left this out.
On the .22 then having the screw flush with the breech block was too much and it was wound out about 1/8" further. I was not comfortable with this so I got a gas torch out , got 1 coil red hot and collapsed it. Screw is now flush with the breach block.
How old is the spring just as a matter of interest? Later I will measure a new one and come back with the length so you can compare it with what you have got .
ATB.
Geoff.

Mine's a .177. I guess the hammer spring would be the same for both calibre's? Not sure how old the spring is as I bought this rifle secondhand.

Thanks.