Discussion in 'Air Arms' started by Baldeagle, Apr 11, 2011.
My AA S400 has dropped to sub 10 ft/ibs, any ideas?
only fill the gun to 170 bar and then try it it will come on the power curve better because the gun oes not hav a regulator fitted,if you fill to 200 bar it will shoot low till the power curve comes in with the knock over valve,
What was it doing before mate ? If its from 11+ then that's a big drop. When was the last time it was serviced ?
It could be something simple like a blown breach seal.
As Chris said. Fill to 160 then test. If it's still lo, can you hear air coming out from the pellet loading probe or beneath the breech block and cylinder upon firing? If so, one of the seals has gone.
Thanks for the replies chaps, gun is just over a year old, normally runs about 10.7/10.8. It has had about 3000 pellets through it. Barrel regulary cleaned but hasn't been serviced. No obvious leaks.
May seem daft so excuse the question, you're not using a different weight of pellet and not doing the maths with the corrected weight?
i would suggest it to be 1 of 3 things.... The o ring seal on the transfer port needs changing, the o rings on the breach end of the barrel need changing or its something to do with the hammer spring.
Try putting a tissue over the bolt / breach housing and fire the gun making sure the bolt is closed. If the tissue moves you have a leak
i have done a few s400's with low power and all of those were new(ish). it was the amount of grease sticking on the hammer and all the other gubbings.
I've had to do 4 of then because of this, all you have to do is remove the breech and barrel and take the back end of the action off clean the hammer slide as the grease on it picks up dirt and sets hard slowing down the hammer which drops your power.
It's an easy fix.