HW90 accuracy problems

[fillythebish]

I got my HW90 with a gasram about 3-4 years ago, it shot beautifully and was accurate with accupels up to 60 yards.

 

But then I stopped shooting and my gun was put away for about 1.5 - 2 years, only being used rarely.

 

Now I have started using it again and the zero had dropped by an inch or more, which might suggest the gasram has lost a bit of pressure.

 

Over the past few weeks I have noticed that the zero does not stay the same, and on 2 occasions it has shifted 1 inch low and also a bit too high in the middle of plinking sessions. It hasn't moved to the left or right, just up and down, almost as if the pressure in the gasram is not stable.

 

The scope hasn't moved a bit, as I have a marker for the clamps and the scope, its solid.

 

So I'm wondering what could I do to troubleshoot it?

 

I'm going to get a Chronograph this week and some more pellets to check if the pressure has changed or is unstable.

 

Could it be the barrel?

 

Could it be the crosshairs in the scope?

 

Could it be the gasram?

 

Also how much do gun dealers charge for looking at air rifles?

[tweedledee]

i would imagine it could be loss of gas though i would still expect it to be accurate even if poi had dropped.i had a 90 and wished i never sold it. great guns. stick it on the chrono and see what it says.i would suggest giving the barrel a clean,just in case there is a build up which has hardened over time. also check the breech seal to be sure it has`nt perished.

[smokin]

sounds like a damaged scope - have you got one to substitute it with?

 

had a 90k and many other theoben rams' as well - even if it had lost some pressure, id expect it to still be consistent in its accuracy.

 

not trying to tell you the obvious but are they your usual (good quality, consistent size and shape) pellets?

 

 

if you can get the adaptor tube to fill the ram - it should be around 50bar iirc - originally filled with just nitrogen i think but air is ok (either a stirrup pump or VERY careful filling with a diving cylinder - remember tho if you do its a small chamber and fills very quickly) - if you overfill you cant cock the rifle and risk burning out the seals - it wont be a FAC rated ram so no silly stuff - just tap the valve stem to release pressure and re check if overfilled - dont lose the small sealing o ring when doing this (and it hurts your pinkies if it hits you from a 50bar blast of air)

 

they really do shoot much sweeter at 10.5-11 ftlbs rather than up to 12 as well

 

hope this helps some

 

 

atb

 

chris