s200 more problems

[BforBarney]

The rifle is shooting double groups now, I'll shoot a 10 shot group and the end result is 2 groups 2 inches apart, they're tight groups but something isn't right, it's nothing obvious like a loose scope ring or barrel, I think the power may be "sawtoothing" any idea's whats happening?

[Raj]

Check the condition of the bolt probe o-ring

[BforBarney]

Thanks Raj, I'll have a look.

[Raj]

Also, check for loose sound moderator (slug trails in the muzzle end) / loose air cylinder / loose barrel band.

[DarrenC]

This has come up before and it's usually the pellets causing the issue. Have you mixed together two lots of the same pellets? I did this with AAFs, same weight and head size but from different batches. The result was two nice groups several inches apart. I sorted the pellets back into two batches and the problem vanished. They had a different POI as you would expect from pellets from different dies. Some pellet manufacturers will also put pellets from different batches or dies in the same tin. I heard of some Superfields having this issue recently. Get a new tin of reliable pellets and try them before tinkering.

[BforBarney]

I shot the rifle with and without the mod, checked the mod also definately not clipping it, and I've tried an assortment of different pellets(pellets which were shooting fine previously), same thing everytime. I changed the o-ring on the bolt there now(such a job, to change one little ring, had to take the scope off and take the stock off), I couldn't see anything wrong with the old ring but when compared with the new one it's definately smaller, I'll know tomorrow if that was the problem.

[BforBarney]

Raj you da man!!!





5 shot groups @ 28yards, in the 1st photo, the bottom left group are jsb 8.4gr, they never shot that well for me, the other two groups are air arms fields 8.4gr, the slight change on the horizontal between the group on the right and the top left is just me re-zeroing between groups, happy out the little o-ring fixed it!!!

[rogers1]

good good!

[Raj]

I have managed to change the o-ring without having to half strip the rifle.

1. Take off the plastic pellet tray which is simple to do if you unscrew the socket cap screws and pull the bolt all the way back - get a helper.
2. You will need one good sturdy sewing needle ... say the biggest one out of an assorted pack ... and a piece of thin rigid wire ... say a straightened out paper clip. Work your way in between the metal and the rubber with the sewing needle, hook the paper clip in the gap you have created and tease the old o-ring out. Just reverse the above for getting the new o-ring on.

This is a known weakness on S200s ....especially if a magazine has been used on the rifle. So glad it worked out !!!

[Geoff555]

Hello I have only had a s200 a short time and so has my neighbor.He has a multi shot adapter and it was destroying the O rings very quickly. Looking at the shape that the O ring goes because of the wide groove in the face of the magazine it acts like a gillatine. My answer was to use a tapered reamer and remove the sharp edge and provide a 'lead' so the O ring wasn't distorted and chopped.
This seems to have provided a complete cure both for him and me. A tin of pellets later and it's still intact.
I am happy, what do you think? Worth a try I reckon.
Cheers.
Geoff.