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Re: Is this S200 performing ok?

Posted: Mon Dec 05, 2016 11:03 pm
by TenMetrePeter
I have temporarily put up a pdf from an out of print book from the 1980's with several suggested left hand positions. Link below .
Hamsters are currently limited to metal skeleton stocks as there is an ISSF 90mm limit from barrel centreline to base of forestock. That is being increased to 120mm in 2017 but you would also need to bandsaw off half the buttstock to comply as the limit of that will be 140mm below barrel c/l to avoid resting the stock on the chest! My MPR would need about an inch sawn off the rear corner of the buttstock which would lose the buttplate T-Nut. Anyway I will never get near any ISSF events so who cares.

https://drive.google.com/open?id=0B5fXY ... V9rNlk5bzg

Re weights, just barrel weights and butt weights up to max total gun weight of 5.5kg. Don't think the 200 has hollow forestock like mine to put weights in.
https://www.youtube.com/channel/UCaCf9G ... A-mGhZQlGw is my MPR which has grown by about 500g.

Re: Is this S200 performing ok?

Posted: Tue Dec 06, 2016 4:37 pm
by Chuck Glider
Some great videos you've uploaded there 10meterPeter. Thanks for sharing. "It can certainly stun a budgie" made me larf! :lol:

Re: Is this S200 performing ok?

Posted: Wed Dec 07, 2016 11:28 pm
by Chuck Glider
I rummaged and found some clear plastic packaging from which to make the washer. I used a 5p piece as a template. Pictures below should be self explanatory. I also cut down the brass support band and removed material from its bottom lower face for clearance. There is also a thin sliver of plastic material fixed with double sided tape on the top face of the brass band to hold the air cylinder.

Re: Is this S200 performing ok?

Posted: Wed Dec 07, 2016 11:30 pm
by Chuck Glider
Construction of washer from random piece of plastic packaging that was lying about. Will test the gun later when I get some time.

Re: Is this S200 performing ok?

Posted: Thu Dec 08, 2016 7:21 am
by Raj
Very professionaly done on the washer !!! Looks better than my film negative for sure. Is it giving you the required pinch on the O-ring while at the same time eliminating play between the air cylinder and the breech body? :)
And the brass bling barrel band (well not so much barrel band anymore ... let's call it the air cylinder band!) also looks the part. Probably also helps you with a bit of weight at the fore end compare to the plastic version.
What are the groups looking like ? How does the rifle feel ?? :P
And finally, where are you based and how are you getting to the next AAOC Annual Meet so we can have an S200 gloating session :lol:

Re: Is this S200 performing ok?

Posted: Thu Dec 08, 2016 8:51 am
by Roger5
Yes, looking very good, come on let's see the groups :) I love my S200. Rog

Re: Is this S200 performing ok?

Posted: Fri Dec 09, 2016 5:07 pm
by Chuck Glider
Hard to find time lately, but today I managed to shoot a few groups. First photo is of 5 pellet groups dioptre sights at 10m using JSB Sport Target, rested on a bag. Anti clockwise from top left (you have to scroll the photo to see all the groups):
A. 3mm c-c, shot with brass bracket in place and washer
B. 1mm c-c, shot with brass bracket in place but without the washer
C. 5mm c-c, shot immediately after B, with brass bracket in place but without the washer

I noticed that without the washer, there was a tiny gap between air cylinder and receiver block. The thickness of the washer exceeds that gap by a whisker as far as I can tell. So, to Raj's question, I think it is allowing the O ring seal to work. As to accuracy, the jury is still out. No time for chronographing - further testing will have to be later. No nasty surprises however.

Actually the biggest surprise for me today is shown in the second photo. I recently acquired a SMK XS12 spring air rifle in .22, for £80 new. Out of the box, I shot these 7mm and 8mm (c-c) groups, each of 5 RWS Hobby pellets at 10m bag rested using OPEN sights- you have to scroll the photo to see both groups. That's pretty good imho for a cheap gun. I really like the balance and sound (a thump, not a twang!) of the rifle too, although of course, at this price, the trigger is just ok. The safety seems excellent - as far as I can tell, it's automatic, easy to reach and resettable. Accuracy and feel is bound to improve as it shoots in and settles. It's a keeper!

Re: Is this S200 performing ok?

Posted: Fri Dec 09, 2016 5:32 pm
by TenMetrePeter
I managed to get a 44 on Tuesday club night. The worst was a 20 because standing without a jacket, whilst you can anchor the elbow on the hip bone to steady vertical hold, it's difficult to stop swaying left to right so you get flyers out to outside the 1 ring. The jacket adds some scaffolding.
Reason for posting is I did notice that your targets are not NSRA standard 10m ones in that the numbering is 1 higher. The Ten should be the dot in the middle not the first ring! So on the previous page I'm afraid you will have to deduct 1 from each shot!

2016-12-06 21.19.36.jpg
2016-12-06 21.19.36.jpg (84.63 KiB) Viewed 4181 times

Re: Is this S200 performing ok?

Posted: Tue Jan 03, 2017 4:52 pm
by Chuck Glider
That's good shooting TenmeterPeter.

I finally got the chance to measure the S200's power curve again. Remember, I'd reduced its power to what is typical for a 10m target air rifle. Group sizes were good. For ease of reference, here's a photo of all the power curves. Oldest at the top, the flattest widest one is the latest. This really shows clearly the effect of reducing power. The curve gets longer and flatter and it appears that the stability of the muzzle velocity improves (data is less noisy). Initially the power was ~10.4 fpe. For the last curve it's ~5.7 fpe.

The start fill in each case was 190bar. As best as I could tell, the fill at the end of the top power curve was ~100bar, and at the end of the second and third it was ~85-90bar. As the cylinder has no pressure meter, the end fill was measured by sticking the pump back on, putting a few pumps in to pressurize the line, then assessing where the needle on the pump's pressure meter settled down.

Also for fun, I've uploaded a photo of my first - and probably last ever - 180 pellet group! JSB Target pellets in .177. For scale, the black circle is ~32mm in diameter. The hole is 12.5mm c-c (17mm o-o).