9 ft lb hw97k that kicks like mule.

[Stevie-L]

I have a hw97k in .177 that is only putting out 9.3 ft lbs and still kicks like its putting out 14 ft lbs.does anyone have any idea what the likely causes are for this.the spring is one piece and is straight and has polished ends.can I shiiiiiite get consistent groups with it.

[Mach 1.5]

How many coils in the spring? Could be a number of things. Mach 1m5

[Stevie-L]

How many coils in the spring? Could be a number of things. Mach 1m5

I would have to go back inside of it and count to tell you that mate I have never bothered to do that

[piggy589]

I had a very tired .22 example with the opposite problem,it could be cocked with your little finger

Breech and or piston seal failure,or just oversprung?.

[Stevie-L]

I had a very tired .22 example with the opposite problem,it could be cocked with your little finger

Breech and or piston seal failure,or just oversprung?.

I've had it on the chrony and it's as consistent as can be.i thought I just could not shoot until I got my hands on my mates Springer and knocked out 5p size holes out to 40 yards with ease off the bench.then I realised my 97 is crap

[Geezer]

Breech and or piston seal failure,or just oversprung?.

You got there before me. Probably one of those three.

[Stevie-L]

You got there before me. Probably one of those three.

When you say oversprung do you mean over powered?also do you mean a loose fitting seal?

[tinbum]

When you say oversprung do you mean over powered?also do you mean a loose fitting seal?

If a gun is overaprung it cannot work effectively and just clatters about making noise and recoil.
Have you changed the spring or preload at all?

[Mach 1.5]

Had a 77K with the same problem a few months ago. Had an 38 coil ox spring fitted so way over sprung and so unable to work properly and doing 8ft lbs. You will need to take the rifle apart for members to help with the problem. Mach 1.5

[eyebull]

If you bought it 2nd hand someone may have shoehorned a big horrible spring in there. Counter-intuitively this often makes springers less powerful and and horrible to shoot.

Could be a number of things though, best to open it up and see. HW's are pretty straightforward to strip down.

[Geezer]

This used to happen a lot in the 80s. I can’t explain the physics, because I don’t understand them, but guys would stuff a big Ox or Titan spring in. Recoil shot up (which those guys imagined = power), accuracy would go to carp, and a chrono test would discover was making lower power than original.

The other possibility is that one of your seals is loose, damaged, or has degraded a bit, allowing air to blow by the piston, or out of the action when it should be behind the pellet. Leading, as above, to a very slammy action. Which maximises hold sensitivity and screw accuracy.

Is it new? Is it unmolested? Has someone “tuned” or “serviced” it? Has it always done this? It sounds like you have had it apart. Did you check the seals?

PS another possibility is a dent in the comp chamber.

[TonyL]

Yep, as per much of the above - breech seal, piston seal or oversprung or a combination of more than one.

A member PM'd me a few years ago about a used HW80 which he had just bought. Very high recoil and low power output. In that case, simply reducing the length of the spring restored the power and calmed the manners.

[flyingfish]

I have just spent 2 weeks playing with the spring in my 97 just to find the seal needed sizing. Shoots nicer with less spring and more accuracy.
Power went from 10 to 12.5 and (with a little help) back to 11.4

[Stevie-L]

Sorry for the late reply.
I bought the gun new and was expecting greatness to be honest and deary me was I disappointed.the twang was unreal and trying to use follow through was like waiting for the smoke to clear after setting a cannon off to see wear the projectile landed.
I took the rifle back to the shop I bought it from and I asked if they were all like that?and I was told they were.i hadnt shot a Springer for 15 years and the best I shot was a Webley exocet which was good as I remember so just assumed the 97 needed little fettling.I set about a polish and re grease.springs were a mess and needed polishing and all the rest of it but it made little difference and it was still so harsh and tangy and,using artillery hold was impossible.

I put a tinbum kit in it which done an excellent job of taking the twang away but it was still harsh as can be to shoot and jumped all over when shot,sight picture movement was a a blur during the firing cycle.it was 11.3 ft lbs at the muzzle so took it down to 10.8 and you couldn't even tell so from there I stuck the short stroke extension on which made the power drop and possibly made it harsher to shoot as well,off that came and I couldn't get the power back and so it's now stuck at 9.5 ft lbs and shooting like a cannon still lol.
I'm pretty sure the piston is sized ok as it passes the tests I know to try to make sure it fits right and I've tissue tested the breech seal so is it now a case of just having a nasty spring all along or are there any other things I should check before trying a new main spring?

Sorry if that doesn't make much sense!I tried my best ha

[bighit]

Does the HW97 have the piston weight the same as the HW99s and possibly others ? If it does and its still in the OP's rifle could it be causing the issue?