Aa s400 not accurate anymore?

[Fireash123]

I have a pre anti T s400 that has not ever had a service with light target and hunting use, it's also been layed up for passed year in my damp shed though it was fully coated in wd40 that I have now cleaned off.
Anyhow after giving it a clean though no air is leaking I have noticed it's not as accurate as it once was.
I was getting one hole groups at 30 yards and now getting 5 pence at best with the same gun. I don't have a crono but will to test ATM. (get one tomorrow.) I have all the seals to do a strip and clean but I don't want to do it if it's worth replacing the exhaust valve as I have not got one yet.
Also I have seen the strip and tune for power but I want to keep well on the side of 12ftlbs can I still open up ports and still balance hammer spring and valve spring but not go over power, or should I just leave the settings how they where?
Just would love to get this gun shooting one hole groups again.
Ps it's been charged via a pump if that's any bearing.
Many thanks Ash

[raygun]

The rifle hasn't had a service in 8 years so although holding air it really does want a coat of looking at. Especially if it's been stood out of use for quite a while.

Replace all the required seals and give the hammer rail a good polish. You will have to reset the power but that's no bad thing.
It should then be as good as it used to be.

ATB
Ray.

[davyt63]

As above,and give the barrel a clean,while your at it.

[poguemahone]

clean the barrel, then re lead it as you do a full chrono string in fps, then take it from there
have you bought new pellets, or are you using the old pellets that you used to use ??
have they been kept in the shed and oxidised slightly ??

[Fireash123]

Arh thanks guys, that's what I was hoping to hear, it's had a barrel clean last night and this even I started fire some shots after posting. Already that seems to be more consistent but still the groupings can wonder a bit.
Think I'll do a strip down and polish as you said and I'll do the trigger too as this feels abit tighter as maybe full of gunk and wd40 lol.

[Fireash123]

Sorry no I'm using the jsb exact as read there quite good. I did try the new accupell hft but they feel like a tin mix and shoot terrible not like the old accubells that seemed to group very tight.

[james79]

You say its been laid up for a year, has the owner as well? Not meaning to sound funny but if you haven't shot for that length of time it could be more a case of the shooter getting rusty than the gun It could just be a case of putting in a bit of range time. Once again I'm not meaning to try and cause any offence, but if you haven't shot regularly for a while it could be a factor

[GrandadG]

You say its been laid up for a year, has the owner as well? Not meaning to sound funny but if you haven't shot for that length of time it could be more a case of the shooter getting rusty than the gun It could just be a case of putting in a bit of range time. Once again I'm not meaning to try and cause any offence, but if you haven't shot regularly for a while it could be a factor

I'll second that!
Got my TX out at at the weekend for the first time this year, i seem to be a bit rusty, (i couldn't hit a cows arse with a banjo at the mo! ) just need practice to get back in the groove

[Fireash123]

How very dare you James lol,

To be fare I have an 180 foot garden and been shooting all week and on a rest and can see that I'm not pulling the gun even with the tight trigger. Though I'm not as good as I used to be my groups should be a lot tighter than they are.

[james79]

How very dare you James lol,

To be fare I have an 180 foot garden and been shooting all week and on a rest and can see that I'm not pulling the gun even with the tight trigger. Though I'm not as good as I used to be my groups should be a lot tighter than they are.

No offence intended (fairly sure you didn't take any) but its always best to look at the weakest link first and in my case at least that's the operator Its frightening how much muscle memory you can lose if you don't keep on top of the practice as my last outing with the 12 bore proved