Why is the HW95 so bouncy??

[oldskoolzzz]

Hi Tony, forgot to mention that I also tried boxed premiers which grouped well and again a tight fit in the barrel. It seems my barrel doesn't like pellets from JSB.

Just done some more pellet testing, this time at 30 meters, I have settled on JSB 8.4, 4.52, pic of my best group, lower hole is the aim point, not part of the group. This is about as good as I can do. Very pleased with the 95 now, this spring has transformed it, completely changing its preferred pellets.

http://imgur.com/gallery/rHV8HEq

Make your bleeding mind up

[maximus]

The pellet preference of the gun has changed with the change of mainspring! The tune of the gun changes the harmonics in the barrel apparently. I can only think that this is what has happened. I have loads of "groups" which I shot with all JSB derivatives and never achieved anything like what it does now.

[oldskoolzzz]

The pellet preference of the gun has changed with the change of mainspring! The tune of the gun changes the harmonics in the barrel apparently. I can only think that this is what has happened. I have loads of "groups" which I shot with all JSB derivatives and never achieved anything like what it does now.

Just pulling ya leg buddy

I don’t even claim to understand Springers for they are the work of the devil & voodoo stuff especially once they are opened up and the experimenting begins

Glad it’s all going in the right direction though maximus

[maximus]

No worries, after a week in the springer wilderness searching for answers I'm just relieved that all is well! Its probably my nicest shooting 177 springer now.

[evert]

The pellet preference of the gun has changed with the change of mainspring! The tune of the gun changes the harmonics in the barrel apparently. I can only think that this is what has happened. I have loads of "groups" which I shot with all JSB derivatives and never achieved anything like what it does now.

My somewhat inadequate understanding of springer mechanics makes me question this, I dont think its barrel harmonics that affect the rifles preference for different pellets. Its more likely that different spring rates and preloads affects how the pressure buildup in the rifle interacts with the start friction of different types of pellets, and that the change is pellet preference is caused by this. But I may be wrong...

[TopDog]

Hmmm. Interesting but confusing thread.

It may help if some rationale was used in determining the required information, Something I found useful when trying to resolve the "Gentle nudge in the shoulder" arguments which proliferated some years ago!

I know I will regret this but I would first suggest that one defines what parameter one is trying to evaluate/quantify and then design some ways of collecting, analysing and relating data to that aspect. Lord Kelvin said it better than I ever could! See Quotation in attached PDF reference! http://freepdfhosting.com/d30e366d7a.pdf

I also include in that PDF sketches showing how the rifle CoG etc affects the behaviour of the action pointing direction. By completing the forces diagram to include for example all the hold and support forces and knowing what that may be at the point of pellet exiting the muzzle one would have all the data one needs (as long as that is completed for the entire range of action/pellet etc variables.)

There you go guys - get measuring! I hope that provides a little food for useful thought!

Stay safe and well
atvb
David

[maximus]

Hi Topdog, can't see a force diagram, just the 3 rifles with the measurements on. Also, whats the sensor, an accelerometer? I haven't got one of them. Of course, most people's evaluation of how the 95 shoots is subjective because they don't have any measurement kit. All I know was that I have always struggled for accuracy with this gun, more than almost any other I own, but to be fair I never shot it stock, went straight to a v-mach kit.

[Drew451]

A very enjoyable thread and good, patient work, Maximus. Im very pleased you've got it shooting smoothly. Is there any discernible muzzle flip and how does it compare with your Diana 34 now?

[maximus]

A very enjoyable thread and good, patient work, Maximus. Im very pleased you've got it shooting smoothly. Is there any discernible muzzle flip and how does it compare with your Diana 34 now?

Cheers Drew, I will do a side by side comparison with the two and see what noticable differences there are.

[Geezer]

Cheers Drew, I will do a side by side comparison with the two and see what noticable differences there are.

Excellent. That would be very interesting indeed.

[jonnyone]

I've been so intrigued by this thread that I dusted off an old early .177 HW85L to put some shot through it to acquaint myself with its characteristics. Unfortunately through having a lot going on at the moment and with poor weather all I've been able to do is shoot the gun into a lead billet indoors.
To be fair the gun seems well mannered. But clearly I would need to chrono it and also try n put some groups together to see how easy (or not) that is to achieve.
I would also like to run it alongside a 34 here to discern any differences. I will say the 85 will have to go some to match the 34 and 38 I have.
In meantime I look forward to your further input maximus
Dave

[TonyL]

Hmmm. Interesting but confusing thread.

It may help if some rationale was used in determining the required information, Something I found useful when trying to resolve the "Gentle nudge in the shoulder" arguments which proliferated some years ago!

I know I will regret this but I would first suggest that one defines what parameter one is trying to evaluate/quantify and then design some ways of collecting, analysing and relating data to that aspect. Lord Kelvin said it better than I ever could! See Quotation in attached PDF reference! http://freepdfhosting.com/d30e366d7a.pdf

I also include in that PDF sketches showing how the rifle CoG etc affects the behaviour of the action pointing direction. By completing the forces diagram to include for example all the hold and support forces and knowing what that may be at the point of pellet exiting the muzzle one would have all the data one needs (as long as that is completed for the entire range of action/pellet etc variables.)

There you go guys - get measuring! I hope that provides a little food for useful thought!

Stay safe and well
atvb
David

Absolutely this and not so much down to barrel harmonics. But you put it so much better than I ever could, David.

So, yes, all to do with pellet start, pellet exit and barrel inclination (controlled by what is pertaining in the cylinder) at point of pellet exit.

[TonyL]

Its probably my nicest shooting 177 springer now.

You'll never appreciate just how much that little statement warms my cockles, Max. Nice one.

See.......told you they can be nice.

[TonyL]

Hi Topdog, can't see a force diagram, just the 3 rifles with the measurements on. Also, whats the sensor, an accelerometer? I haven't got one of them. Of course, most people's evaluation of how the 95 shoots is subjective because they don't have any measurement kit. All I know was that I have always struggled for accuracy with this gun, more than almost any other I own, but to be fair I never shot it stock, went straight to a v-mach kit.

And now it's shooting smoothly and accurately, so all's good.

To be fair, most springer shooters will judge a springer's firing cycle based on perceived feel.....and we're all different. To my mind, if it's not twanging and crashing and harsh and as long as it's accurate, me happy.

Before Jim started getting more "digital" with his measuring equipment in his fine articles, he used a pencil taped to the action of the recoiling gun (the pencil obviously able to contact with paper) to measure recoil and surge. Once you know the weight of the internals as compared to the all-up weight of the gun, much could be learned as to what was happening inside the cylinder. Not exact as what he can do now, but eye-opening nonetheless.

[Geezer]

The best thing about this thread is the idea of a shoot off between the 85/95 and the D34/36/38. Very interesting.

Ideally, add in some others, like the 80 and FWB Sport.