Is this S200 performing ok?

[Chuck Glider]

I had a look at other threads on floating barrel. As an archer, I can appreciate two things. First, that the bow-arrow-shooter is a system, just like gun-pellet-shooter. Second, that consistency is king and any disruption or interference in the shot cycle is bad.

So, if the air cylinder is vibrating on each shot, or the barrel works consistently when held only by the receiver, or both, then it makes a lot of sense to me to try to suppress the vibration and break the connection between air cylinder and barrel.

Negative film gives away Raj's age perhaps!

Gun is currently at 7.8 ftlb at peak of power curve. Next time I take the stock off, I will open the choke, reduce the hammer spring power to around 6.5 ftlb, ca. 610 fps, then reduce the choke to get it to 575 fps, ca. 6 ftlb. Clean inside of barrel, and fit the new trigger blade. I MAY also do some metal work on the brass band, before I fit it, because I like the bling so much! I may use fibreglass tape pads to suppress the cylinder vibration, as I ran out of negative film some years ago Raj. Then retest... (Classic changing of too many variables at once, but heck life is short!). I have some JSB sport target pellets coming and being "Czech mates", I expect them to work well in the s200.

My understanding is that flathead pellets are intended/designed to be shot at around 560-580 fps. Is that right?

[Roger5]

10mtr Peter might be your man for pellet question, come on answer the chap. Rog

[Blackbaronfish]

I had a look at other threads on floating barrel. As an archer, I can appreciate two things. First, that the bow-arrow-shooter is a system, just like gun-pellet-shooter. Second, that consistency is king and any disruption or interference in the shot cycle is bad.

So, if the air cylinder is vibrating on each shot, or the barrel works consistently when held only by the receiver, or both, then it makes a lot of sense to me to try to suppress the vibration and break the connection between air cylinder and barrel.

Negative film gives away Raj's age perhaps!

Gun is currently at 7.8 ftlb at peak of power curve. Next time I take the stock off, I will open the choke, reduce the hammer spring power to around 6.5 ftlb, ca. 610 fps, then reduce the choke to get it to 575 fps, ca. 6 ftlb. Clean inside of barrel, and fit the new trigger blade. I MAY also do some metal work on the brass band, before I fit it, because I like the bling so much! I may use fibreglass tape pads to suppress the cylinder vibration, as I ran out of negative film some years ago Raj. Then retest... (Classic changing of too many variables at once, but heck life is short!). I have some JSB sport target pellets coming and being "Czech mates", I expect them to work well in the s200.

My understanding is that flathead pellets are intended/designed to be shot at around 560-580 fps. Is that right?

I have used the sticky pads that are made for sticking windscreen mirrors on to good effect.

BBF

[TenMetrePeter]

My understanding is that flathead pellets are intended/designed to be shot at around 560-580 fps. Is that right?

German F marked weapons which represent the top end 10m target kit run at 5.5 ftlbs or less (individually certified by model). 3 ftlbs is not unusual for ssp.
8.3 grain R10 would go at 540 max. ok 7 grain at 580 is in the limit but too light for rifle really.

Screen Shot 2016-11-26 at 11.41.47.jpg (67.73 KiB) Viewed 3930 times

[Chuck Glider]

I did the things mentioned in my November 26th post. Specifically, I loosened the hammer spring cap screw by 1/2 a turn, and adjusted the venturi to bring speed to 564 fps using JSB Sport Target wadcutter pellets, 8.02gr (5.66 fpe). Attached a photo of a 5 pellet group at 10m, Dioptre sights, rested on a bag (not clamped). Lovely round, small group. Currently the front support band is plastic, cut down like Raj's, filed for clearance underneath. I've made some effort at dampening the air cylinder with tape on the inside of the support band. But that's just a prototype, the final one will be the brass one - not yet had time to do the metalwork on it, but I will at some point.

[TenMetrePeter]

Looking good now.
It does reflect on the skill of the Olympians to get every shot scoring 10.9 to 10.5, i.e every shot virtually inside the 10 ring whilst standing.
I am happy if I clip the 10 ring 1 out of 5 shots.

[Raj]

That is sweet. To elaborate on the film negative trick ... You can improve the group further by adding a couple of layers of film negative (cut in a washer shape) and inserting between the Breech Body No.13 and the brass firing valve end plug No.38. You need to put enough layers so that the sealing of o-ring 'Cylinder to Body Seal No.39' is effective but eliminate any play between the Breech Body and the air cylinder assembly. Believe me, there will be some now Once you do this, the rifle will feel an sound very different - more solid.

In this rifle, the firing valve (and hence the movement) is fully contained in the air cylinder which is itself attached to the breech body with threads and a face seal. Every time you fire, the leverage of the heavy and long air cylinder is used to jerk the breech body as the hammer strikes the valve. Since you have fettled the barrel band, this shake is now free to be magnified through the breech body to the barrel. If you arrest the jerk, you will have an altogether better level of steadiness and the group will close in further!

Costs nothing, takes minutes and can be reversed if you dont like it. Give it a try and post us another group. Also, when you do this group, tweak your scope so that your POA is not on your POI. Then you will be able to see what the true precision of your set up is instead of trying to imagine where the POA centre should be after your first shot of the group.

[Chuck Glider]

Thanks Raj. I misunderstood what you meant about film negative. I get that - it's just like a damper washer (as is used in archery stabiliser setups). Thank you, I will try that. Also, re: POA/POI, I'm using diopter sights, so always centering the roundel in the ring. That group was before I had zeroed in.

Totally forgot, I had two BIG questions for folks.

First one is technical, for anyone knowledgeable about S200 triggers! My trigger seems great now with the Rowan blade, but what I noticed today is an inability to de-cock safely. This is what happens: I hold the bolt out, press and hold the trigger, slowly allow the bolt down and then when I release my finger from the trigger, it releases and dry fires some air! What is wrong?

Yes 10meterPeter, Olympians are amazing...in all sports! Just watch the Koreans at archery... And air pistol shooters are freaks!

So, second question is about MY shooting I'm a total beginner, never been to an air rifle club. As I mentioned previously, I do enjoy archery and have some ability at that (county level many years ago). Today, I had a go at 3 position shooting for the first time ever. I used my S200, JSB Sport Target 8.02gr @ 10m outdoors, with dioptre sights, 4mm ring insert, 10 pellets at each position. Scores for Kneeling, Prone and Standing: 82+91+75 = 248 respectively (248/300). Photos of cards attached - these are not ISSF targets, but the Bisley ones, so the 10 is bigger than ISSF! I really enjoyed it and found it surprisingly physical. What do you think? Is this first effort any good, rubbish, or what? Also any tips gratefully received.

[TenMetrePeter]

better than I can do at the moment. 82 ex 100 free unsupported standing would be respectable club league div 2 stuff. Probably only 2 at our club could beat it. Jacket and glove make a big difference. My average in 2004 with a canvas jacket and a Walther lg200 was 80

[Chuck Glider]

Ah, that's really encouraging, thanks 10meterPeter. (I have sorted the trigger by the way - see separate "S200 trigger design" thread on this forum. The rear stop screw was too far in and now that I've unscrewed it a bit, it can be de-cocked safely). I need to get a decent Knee roll. At the moment, I'm using a rolled cushion, but it's way too spongy and doesn't support enough. Standing is SO much harder than the other two positions. It's hard to find a comfy, stable, repeatable position for the supporting hand/fingers/thumb. I can completely understand why people use "hamsters" and those stiff "exoskeleton" gloves and jackets.

Thanks for all the pointers and help. Apart from attempting to improve on my first 3 position effort, I want to do the brass support band mods, the air cylinder damping mods and run another power curve, now that I've got the power to roundabout where it should be. What a great gun this is!

Is there any way of making it a bit heavier though? I feel that may be helpful to reduce how much it sways about. It's a lot lighter than my Walter LGV Challenger.