Why is the HW95 so bouncy??

[TonyL]

Yes, above all other qualities or traits, accuracy has to be the #1 goal.

[robs5230]

There's quite a lot wrong with the 95 out of the box.

The factory setup is pretty poor. They've just bunged a spring in with the hope of it being safe at sub12 (once the factory lube has burned off). But before the lube has all been combusted, the efficiency of the factory seal will have reduced, by it being hardened by the combustion.
Inefficient seal - harsh shot cycle. Thats if the seal hasn't already been compromised on assembly, by being rammed past the razor sharp cutouts in the cylinder, by some bloke in the factory.

Barrel length - now 310mm. Supporting the now accepted fashion for silencers on springers, and also compromising efficiency, with the shorter barrel producing less power.
The 410 barrel with the muzzle weight, being more efficient can produce a far softer shot cycle.

Lots of methods have been commonly used and described on here to "tame" the 95. Most just masking symptoms and making them appear better.
Obviously a set of well fitting guides will reduce twang. Short stroking quickens the shot cycle by reducing the amount of air available to be compressed (at the expense of increased preload needed to make power back up, possibly increasing the harshness of the shot cycle).
Piston sleeves. Another way of reducing noise, often used to calm a badly fitted spring.
Over lubing. Slap it all over, and boy can it feel smooth. It will shake off, migrate to the compression chamber and start shagging the seal all over again, so back to point 1.

The factory swept volume. Not ideal, but no disaster by any means.

The factory plank. Slack rake of pistol grip compromises any kind of decent trigger control, from what is a very good trigger.
Crap comb height for scope use, just about tops the lot off.

So in summary, out of the box, you end up with a harsh, boingy item, thats ergonoically poor.

But its all sortable

https://flic.kr/p/2kvQ8Hk

[robs5230]

So now we've established that an out of the box is a bit flawed, what can we do about it?

Just peg on with it is one option.
The shot cycle will calm down a tad, when all the factory lube has burned off, and you'll learn to live with it if you shoot it enough.
Choose the right pellet. I hear lots of stuff about finding the right pellet for the barrel. I don't really accept that. I think if you're going to shoot an out of the box rifle, you need to find the right pellet for the shot cycle.
Differing pellet brands and types, will all make the shot cyle different. Getting the right balance of resistance for the piston, will certainly improve the shot cycle and accuracy.

Starting to think about sorting the rifle, properly, is my option.
Trigger control. I have normal sized hands and fingers. If I were to use a factory stock, I'd fit a set back trigger blade. You'll never have good accuracy with poor trigger control.

The stock. Ergonomically, I don't get on with the factory stock. A CS500 sorts that.

The action. I've not shot an out of the box springer in over 25 years, probably more.
A basic strip clean and deburr is number one.
A new seal. I'd always chuck the one that came fitted. Check the fit of the seal you wish to use. Some factory seals can have an ok fit, some dont. Too loose, its no good, too tight, it needs sizing. There are after market options. Some good, some not so good, but the priority is fit.

Choose a spring. In a 95 I'd start with a 97 export spring of 3.1mm wire. Dehorn the closed ends of the spring. Stick your finger in each end of the spring and spin the spring on your finger. Wash the blood off, apply plaster, and get the file out.
Get guides made for the spring. Fit needs to snug but not too tight.
Ensure you have a power washer, for behind the top hat and between the spring and the base of the guide.

Choose a pellet you want to use. Say what ??? Yep, choose the pellet you want to use. They're pretty good barrels, and will shoot most pellets well (when set up right).
I shoot for pest control and prefer a light pellet so I always tune specifically for JSB express. I don't go by the batch theory either. Mine shoot any batch, any tin, straight out of the tin.

Assemble and check power.
I use moly sparingly. Just on the guide, top hat and spacers, the rest running dry. Apart from the cocking shoe that is.

I tune for express, so its easy for me. I aim for a power figure thats safe with express and lighter pellets, so 10.5 for me with express.
Start cutting the spring and refinishing bit by bit, until power drips where you want it, then make it back up with a spacer.
Its now optimised for the pellet.
I dont compress any coils other than the ends, and prefer all the spring length to be active.

I've found when I do it this way, all other common pellets, are way less efficient.

This works for me.
My 95's don't flip, boing, jump, dance or anything else.
They shoot asas well from a bag (hand rested or not) as they do freehand

[TopDog]

Spot on!! As a little exercise some while ago I did some recoil tests with my Test 80, light hold, firm hold, butt held firmly against cabinet (semi-rigid) and butt held firmly against wall (rigid). Will dig those out and post a collage of the results overlaid!

Action liveliness is of no real consequence as long as it, and the rifle/shooter interface, is the same every time. That, I think, is the essence of a springer and why they are so much fun to shoot! I always turn to springers for pleasure, the PCPs are for the clinical work!

atvb
David

Here's the hold sensitivity file I promised. I chose the results for the BrumBow since it is the medium weight barrel cocker which displaced the HW95 as my favourite and had not done the HW95.

http://freepdfhosting.com/d09abfdb29.pdf

Happy airgunning!
atvb
David

[TonyL]

Brilliant graphs, David. Thank you for sharing..

[maximus]

I'm thinking that tomorrow will be the day of the totally non scientific, subjective head to head shoot off between the reformed 95, the 34 (but which one, the one that likes FTT or the one that likes JSB?) an 80 (but which one, short stroked or standard??) and a new model FWB Sport. All guns home tuned and all different characters

[averageplinker]

I'm thinking that tomorrow will be the day of the totally non scientific, subjective head to head shoot off between the reformed 95, the 34 (but which one, the one that likes FTT or the one that likes JSB?) an 80 (but which one, short stroked or standard??) and a new model FWB Sport. All guns home tuned and all different characters

Sounds like great way to spend the day to me!

[TonyL]

Sounds like great way to spend the day to me!

Absolutely.

Looking forward to seeing the results, Max.

[maximus]

Right, group test completed as promised. Bit of a marathon and the muscles in my back are aching like buggery, hope you appreciate my suffering in the name of non scientific research! Winner in accuracy stakes for me is the FWB. Last gun I shot and was flagging by then but it just kept putting them where the crosshairs were. One group in particular is barely 2 pellets wide. Amazing for a 5 shot group standing supported at 25 yards.
Nicest gun to shoot, probably my 95 although still not that forgiving, felt happier with the 80 till I pulled the trigger.
I started by trying at 30 meters but that was too far for me today!

https://i.imgur.com/eMpkKn5.jpg

https://i.imgur.com/2ew80WW.jpg

https://i.imgur.com/adPeKdJ.jpg

[TonyL]

Hey Max, thank you for your fine efforts and selfless sacrifice.

I can't view those images properly at the moment as I'm looking in on my phone. Will hopefully get the chance to look in on the iPad later.

How standard is the FWB? I seem to remember you posting when you first got it? Great that that has shone in this test when quite a few nay sayers doubted its credentials.

[maximus]

Hey Max, thank you for your fine efforts and selfless sacrifice.

I can't view those images properly at the moment as I'm looking in on my phone. Will hopefully get the chance to look in on the iPad later.

How standard is the FWB? I seem to remember you posting when you first got it? Great that that has shone in this test when quite a few nay sayers doubted its credentials.

Hi Tony, thanks for the appreciation! The FWB just has fitted guides and top hat etc. My initial problems with it were all around recoil which is never going to be tame with a 30mm piston gun but changing the spring helped tame it a bit and the accuracy is second to none with JSB 4.53's
I think my Diana 34K may of been let down by the FTT's or me. I'm going to give it some more range time as I know I've done better with it in the past.

[evert]

Choose a spring. In a 95 I'd start with a 97 export spring of 3.1mm wire.

Interesting; why the 97/77 spring and not the original?

[TonyL]

Hi Tony, thanks for the appreciation! The FWB just has fitted guides and top hat etc. My initial problems with it were all around recoil which is never going to be tame with a 30mm piston gun but changing the spring helped tame it a bit and the accuracy is second to none with JSB 4.53's
I think my Diana 34K may of been let down by the FTT's or me. I'm going to give it some more range time as I know I've done better with it in the past.

A fine looking collection of boingy little beasties, Max.

And some excellent shooting there and some very fine results. With a less "intensive" session and not switching between guns so much, I bet consistency of grouping would improve even further, although I appreciate the reasons for trying to accomplish on the same day, conditions etc. And those best groups from one or two candidates are simply stunning. Again, thanks for sharing.

[robs5230]

Interesting; why the 97/77 spring and not the original?

Just had better experiences with that spring spec over the years.
Better fit in the piston.
Ends up with little preload.
I find it easier to fine tune than the factory one.


My current one isn't that spring (yet). The rifle's a V-mach tuned one but with HW seal.
I've done a little work on the spring and replaced the over tight guide with one that I've made, and for the minute, its a right result.

Initial testing shows it to shoot very well, and it has a 6fps max spread over the skan, but I need to get it out to the club range and get it plotted out.
At that point, I'll decide whether the V-mach spring stays or goes.
The cycle is a little snappier than I like, but recoil is low and sight picture undisturbed when shooting.
We'll see

[TonyL]

Understandable, Rob. Many different ways to achieve similar results, seemingly. Some people have even had great success with using 77/97 springs in sub-12 80s. And the TX Mark3 spring seems to be finding its way into many a piston.