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AA s200 query

May 16 2017 at 12:36 AM
peterdulux  (Login peterdulux)

Help me understand something.

I have an older version of the AAs200.

I backed out the restrictor grub screw 1.25 turns and cranked in the hammer spring half turn and had it up to 700ish fps.

Then I filled the cylinder and it dropped down to low 500's. So I cranked in the hammer spring to two full turns and ended up with 600ish fps.

What gives? Am I missing something?

This message has been edited by peterdulux on May 16, 2017 12:37 AM

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(Login Diamondback)

S200 power question

May 16 2017, 5:47 AM 

What caliber, what air pressure when you got 700 fps, & what air pressure when you got lower velocities of 500 fps & 600ish fps?

Also, are you sure the restrictor screw you turned was the actual restrictor screw, or a cover screw over the actual restrictor screw (like the AA S4XX series), or a lock nut around the adjuster screw? I have never adjusted mine, but the usual restrictor screw setup looks like an allen screw with a lock nut around it. If it’s pre owned, no telling what a previous owner or 2 did to it.

There have been different versions of S200 produced over the years. It seems a little confusing because depending on where you read, the Sporter, Target, FT, & Hunter names & specifications are used & interchanged, often incorrectly. There have been different S200 MK’s, power output versions, different stocks (1 piece brown wood, 2 piece brown wood, 1 piece red laminate, 1 piece brown “Hunter” stocks, some adjustable & some not), some came with gauges, etc.

I’ve mostly read about the 12 ft lb version (Sporter?), either in 1 or 2 piece stocks or 1 piece red laminate stocks, that usually come stock shoot 177’s approx 800 fps or 22’s approx 625 fps. I’ve read posts where these were adjusted from around 8 - 18 ft lbs.

I have also read of a lower power 177 caliber version (10 meter Target, if you will?) that averages around 7 ft lbs in 177 (not made in 22 according to some posts but I’m sure parts can be swapped). Posts indicate it adjusts from around 6 to 8 ft lbs, or from just over 500 fps to around 675 fps. Kinda sounds like yours...is yours 177?

There has more recently been a Hunter model variation that is supposed to come stock shooting a 22 caliber pellet at 20 ft lbs, or around 800 fps.

It’s possible yours has been adjusted, or even modified if it’s pre owned, or it may have a problem (worn spring, failing seal causing restriction, inaccurate gauge, etc).

There was a great series of S200 modding posts by Bobhttp://www.network54.com/Forum/79537/message/1317004877/CZ+200S...+Tuning+for+Power...+Lots+of+Pics%2C+Stats ) where he took the restrictor screw & replaced it with a longer one that had the tip profile altered, so that when closed fully it really choked off the air flow a lot more than stock. By tweaking other areas power or consistency could be altered quite a bit. Our Brother Robert / Gubb33ps has done lots of great posts on them as well.

Maybe contacting CZ with the serial number & any other pertinent info might turn up more info on your S200?

Great little rigs...I have 3 myself happy.gif

This message has been edited by Diamondback on May 16, 2017 5:48 AM

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George Rapozo
(Login Keokira)


May 16 2017, 5:17 PM 

i have an older model s200 . it has no pressure guage and has a funkie fill nipple. I just had it on the crony the other day and it was shooting jsb 8.44 gr pellets at 820 fps. i have never touched the restrictor adjustment screw. and this gun is
absolutely deadly accurate. it will stack pellets on one another at 20yds with no problem. I have put stink stuff on a target at 20yds and from a rest shot flies on the target. i bought this gun used 5yrs ago'

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(Login gubb33ps)

Make it simple

May 16 2017, 5:56 PM 

Older one....likethe two-piece stock style? And when you say "filled it up", to what pressure?

Evidently yours has the adjustments (transfer port screw and striker spring) and isn't "tamper proof" (thankfully).

Turn the transfer port restction screw out another turn and a half.

You really don't need to have it in the stock to adjust it...can still shoot over a chronograph with it stockless...and it speeds up the process considerably.

photo f20ba3ef-976a-485c-b945-f8961f184a10.jpg

Don't want it shooting it's fastest at the top of the fill and declining in speed, so you'll have to shoot 10-15 shots to see what direction the velocity change is going: High speed declining: reduce the striker spring tension, refill, and try again. Low speed and climbing: increase the striker spring tesion, refill, and try again.

Ideal would be for it to end up a little slow at top pressure, slowly climb, peaking at something like shot 20-25.

If you're happy with the speed, then refill and start screwing in the transfer port restriction until you notice a decline in velcocity....then back it back out a fraction of a turn. If you want it a little lower speed, keep turning the restriction screw in until you get there.

One of the two I have (an old .22 AA s200) had that funky industrail type fitting...looks more at home at a car garage then an airgun...but it still works, so I just leave it alone.

DSCF1962 photo DSCF1962_zpsbb35f87f.jpg

Found my two don't really "like" high speeds....they get real wastful of air and tend towards short shot counts when pushed past certain speeds/energy. Thinks tend to take a dive with the .177 version somewhere about 15 foot pounds (but make delightful 12 foot pound rifles) and the .22 gets air-hoggish past 18 foot pounds.

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Bob D.
(Login MB-BOB)

Yes you might be missing something...

May 16 2017, 7:18 PM 

You might be missing the o-ring on the receiver end of the tube.

Or you might be missing the probe o-ring.

Or either one may be split, and leaking air upon firing.
[linked image]

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(Login peterdulux)

Re: Yes you might be missing something...

May 16 2017, 7:29 PM 

Getting back to you guys. Mine is the older UK, two piece stock. No anti tamper.

Pressure was at about 1/3 full when I first turned out the restrictor screw. was up right at 700's.

Then filled it to around 180 bar, (no gauge), nitrogen with regulator set to 180 ish.

Then it dropped way down to low 500's. Then I turned the hammer spring in two turns and ended up at 600 when I stopped and called it a night.

Something else, I bought it with two air cylinders, original and an Avanti cylinder. With the Avanti cylinder, before playing with settings, it shot 30 fps faster than with the original AA cylinder.

Any ideas on that one?

And yes it is a nice little gun for sure. Oh, it's a ,22

O rings look ok.

This message has been edited by peterdulux on May 16, 2017 7:33 PM

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(Login gubb33ps)

Pretty much outlined the "why"...bascially have 3 tests there.

May 17 2017, 8:51 PM 

First test was at about 1/3 pressure and it shot in the 700's.

Second test was at full pressure (3/3rds) and it shot in low 500's.

Third was increasing the striker tension by 2 turns and getting to 600fps.

Fill it full again, increase the striker spring tension by 1 full turn, and shoot 20-30 shots....you'll see the direction it needs to go.

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