Help needed for my AA S410 power regulation/servicing

[Shoot4Toffee]

My S410 chrono'd at 9.4 ft/lb, with 180 BAR and dropped to 6ft/lb at 150 BAR. I have stripped the bolt action, and triger housing, removed a compacted bit of dusty grease from the action, fitted an "O" ring into the transfer port (to the barrel) and the thing now chrono's at 4.5 ft/lb at180 BAR! I guess the next step is to check the air valve for obstruction, and the regulator behind the anti-tamper access.

Expert opinion and instruction on the above would be appreciated, PM me if your information is not for general consumption, I want to bring the power up to legal limit, I have an assortment of bolt springs, but as the loss of power is so great, other problems need to be eliminated.

Thanks, Tom.

Before sending it for service, I want to learn all I can about the mechanism.

[lightning22]

Send it to Ben Taylor for a tune/service if return to the original seller isn't feasible.

Rich

[Shoot4Toffee]

Will get a quote, but I would prefer to do all I can first, and learn about the mechanism. (I know curiousity killed the cat, but I will be cautious)

[lightning22]

I would guess at about £70, It could be something as daft as a broken hammer spring

[Guppsta]

My dad has got a similar problem with his s410, it just dropped to around 6 ft/lb one day. it has had all seals replaced but still the same. if you find out what it is, please pm me and let me know so i can try it with my dads,
Guppsta

[Shoot4Toffee]

My dad has got a similar problem with his s410, it just dropped to around 6 ft/lb one day. it has had all seals replaced but still the same. if you find out what it is, please pm me and let me know so i can try it with my dads,
Guppsta

I am going to disassemble it again, and see if the apertures are in alignment. I expected loose bolt housing screws and the bit of dirt were to blame, so I'll go further this time.

I have a set if hammer springs, but the original is in good order so not sure if the spring could be causing the problem. I have a second S410 working well, so could try a swap of the bolt/hammer actions' to see if that sorts the power. - Just hope is doesn't cause the 2nd to fail!

Cheers, Tom.

If all else fails, I'll pop it into Ben Taylor (www.bentaylorandson.co.uk) The website makes very interesting reading

[Gwylan]

There my be some grit or swarf stopping the valve opening correctly, with the cylinder empty of air, and the rifle uncocked, try blasting some air through from a bottle. Has someone been playing with the firing pot adjustment? Don't try this , unless you know what you're doing.

Gus

[Shoot4Toffee]

I disassembled the gun again, and with 90BAR to discharge from the cylinder, I manually used the hammer to discharge air. (Don't do this at home folks!) Heavier blows released more air, so I ascertained that a heaver spring would give the required result.
I have replaced the spring, and now get 11.2 to 11.5 ft/lb output!

This may or may not be a long term fix, I will put a tin of pellets though the gun and check for consistency.

The original spring looks and feels fine, so I am at a loss to understand the sudden loss of power. I found a thin layer of oil in the cylinder, but did not dismantle the air valve or access the firing pot.

Thanks to you all for your suggestions, I will visit BTAS next time I have a free half hour

[Gwylan]

Are you having us on...! Under NO circumstances should there be oil in the cylinder...! This forms an explosive mixture...! There's something very funny going on here.

Gus

[Weevie]

Thanks to you all for your suggestions, I will visit BTAS next time I have a free half hour

Hmmm you may need more than half an hour...if what I hear is correct Ben does like a chat

[merlin]

Are you having us on...! Under NO circumstances should there be oil in the cylinder...! This forms an explosive mixture...! There's something very funny going on here.

Gus

could it have got their from someone using a dodgy pump ....if thats the case could be all manner of crap as well got thru.....sounds like it needs a good clean out.

[Shoot4Toffee]

I think it was a rust proofing coating, prob a high melting point grease? I trust the guy who sold it to me, and it didn't explode when I filled it

The cylinder seal makes a lot of squeeking as it fills, is this normal?

I do expect BTAS will take more than a short visit