Inconsistent S200

[maff]

Hi
My son's air arms s200 seems to have developed a problem. After about 4 or 5 shots the impact point drops by about 2 inches (this is at 30 yds) The weird thing is that after the shos dropped they wouldd then be ok for a couple of more shots and then drop again. I'd say it was him not shooting properly but he has never had this problem before and he is quite a good shot. He tried my S400 and he was OK wit that. The S200 was full to 190 but after about 25shots had dropped to about 100. The air cylinder has always only been hand tightbut the shop I ought the gun from said this isn't a problem.
Anyone have any ideas what could be wrong before I take it back to the shop as it's still under warranty.
Cheers.

[Gwylan]

Make sure the cylinder is tight. Check that the cocking lever on the LHS of the action isn't being fouled by the stock being too tight on that side. When you pull the bolt back, the lever moves back. When you push the bolt forward, the lever should return all the way to its forward position. If it doesn't, some of the hammer's energy is wasted. You may need to remove some wood from the inside of the stock.

Gus

[martyntin]

Make sure the cylinder is tight. Check that the cocking lever on the LHS of the action isn't being fouled by the stock being too tight on that side. When you pull the bolt back, the lever moves back. When you push the bolt forward, the lever should return all the way to its forward position. If it doesn't, some of the hammer's energy is wasted. You may need to remove some wood from the inside of the stock.

Gus

I had this problem on 1 of my s200s when i changed the stock and it was the lever not returning forward after cocking before taking the shot and easily fixed.

[maff]

Thanks for the replies. Just checked the cocking lever and it seems to be OK. The air cylinder is tight. I tightened the cylinder just after the problem arose but it didn't seem to make any difference. I've even checked that the scope is not loose.

[Rich]

If you can borrow a different cylinder, try that. If the problem goes away then there is something up with the firing valve in your cylinder.

Check that no oil is on the hammer components.

[ChrisC]

I think that the problem may be internal so the best bet is to return it for repair under warranty. If you have any problems and can't get it checked under warranty then drop me a PM and i'll see what i can do...Chadd isn't too far from me.

Oh....unscrew the cylinder and see if you you can hear any air leaking from the end that screws into the breech. That's a very common point for leaks. A leak there can sometimes be cured by tapping the valve with a large allen key as this quickly opens the valve and allows a blast of air to blow out any trapped debris.

[maff]

Thanks for the advice chaps. I'm taking it back to Manchester Airguns tomorrow. As it's under warranty they may aswell look at it.
Cheers

[maff]

Got the gun sorted. Took it back to Manchester Airguns and they took the air cylinder off to reveal the rubber o ring was distorted, it seems to have been glued in place which had made it go hard and brittle. They put a new one in and it's been fine since. Thanks for all the replies and advice chaps.