HW98 recoil issue

[Mr H]

Hi guys
Im having trouble with my HW98.
It is running at 760fps, has a custom guide and tophat and is fitted with a v-mach seal.
The seal was sized on a lathe and properly lubed.
My problem is the recoil,it feels very harsh/snappy.so much so that after the shot you are way off target if looking through the scope.
It almost feels asiff the seal is not sealing properly,but it felt exactly the same before the seal was sized.
Any advice would be appreciated

[Motorhead]

Do a tissue test on breech seal ... If it leaking will have effect on velocity and shot cycle smoothness.

[nced]

Hi guys
Im having trouble with my HW98.
It is running at 760fps, has a custom guide and tophat and is fitted with a v-mach seal.
The seal was sized on a lathe and properly lubed.
My problem is the recoil,it feels very harsh/snappy.so much so that after the shot you are way off target if looking through the scope.
It almost feels asiff the seal is not sealing properly,but it felt exactly the same before the seal was sized.
Any advice would be appreciated

 after the shot you are way off target if looking through the scope.
Hummmm.......I thought that was NORMAL with a springer! Anywhoo, my home tuned and oring sealed .177 R9 is similar but I'm shooting 7.9 grain CPLs at 850fps except for the last couple months after breaking my last .120 wire aftermarket spring (spring had 10s of thousand of shots). I'm currently shooting CPLs at 880fps after replacing the .120 wire spring with a .125 wire spring from my "parts bin".

Anywhoo.....it's still rather accurate at those speeds and here are a couple 50 yard pics of a target I shot with the R9. All groups were shot sitting on a bucket resting the gun on cross sticks (not bench rested)......
Notice the CPL group in the upper left corner when comparing different pellets.


A 5 shot group on a field target paddle at my back yard practice range in a light variable side breeze.........


The next 5 shots on paper........


While not exactly "PCP quality groups" I'm still pleased with them even though I lost the sight picture through the scope with each shot. The "secret" if there is one is to concentrate on having the scope crosshairs return to the aim point with each shot. Sometimes I can do this when I'M shooting well, usually I can't but I keep trying! 

[palonej]

Hey Mr H and welcome!!!
Is she shooting accurately!!! How do the chrony numbers look over a 10 shot string??

[Mr H]

Velocity is low 750 and hi 760fps over ten shots.
You have to work alot harder to get good accuracy.
I think i am going to try thr tissue trick today

[Mark 611]

are you experiencing piston slam? it sounds like to me the piston seals is to lose? or you could have a bigger problem, HW guns are known for this from time to time, in factory trim OEM parts they perform ok but when you up the power or change things like piston seals this problem reveals itself, some compression tubes are out of round from the factory and the only way to fit it is to sunnen hone the tube to make symmetrical so the piston seal seals correctly, if you check ARH's site JM talks about this problem, just a thought of something you my want to look into! also check your breech seal

[Mr H]

Does sound like the piston is slamming. Breach seal is ok. How can i check if the cylinder is out of round?

[Mark 611]

you need to get a long telescoping gauge and measure the tube in several place just like a cylinder on an engine! or you can try a vacuum test by pushing the piston and seal with you finger over the transfer port hole to see if it holds pressure but some times that won't always tell if the tube is out of round! because of where the seal is in the tube at the time of compression, most of the time when an out of round tube shows signs of this condition is when the piston is under acceleration from the spring, IMO I would try to fit another piston seal and let it have about 2 to 3LBS of pressure to push it down the tube and let it break in on it own, things change allot when you add moly to the seal, that said if the seal is on the small side of fitting the tube just enough add moly and things get a little lose! and if their any out of roundness to the tube it will compound a seals ability to hold tight to the cylinder walls, thus causing {piston slam} and loss of vacuum which is why your velocity's are all over the place and felt recoil is more pronounced JMO