Why is the HW95 so bouncy??

[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]

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.

[TonyL]

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.

Ooo-er.

[maximus]

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.

This can be arranged as I have 177 80 and a new sport in my collection. I might do a warts and all set of 5 x 5 shot groups for each rifle and see how we go.

[TonyL]

This can be arranged as I have 177 80 and a new sport in my collection. I might do a warts and all set of 5 x 5 shot groups for each rifle and see how we go.

Ah, that'll be something to look forward to seeing.

So, when you started this thread off, did you envisage it becoming the epic classic that it has become?

[PCPShooter]

My favourite 95 combo is a v mach tuned one (which probably involves a tad of TP widening to match the shorter faster spring) coupled with a heavyish mod - EB Sirocco or PH, with a scope of 50mm AO objective as this meets my cheek position best and I feel indulged in the nice wide angle of view often afforded.......

When set up optimally a 95 in any cal is smooth and pleasant to shoot at uk power, and not jumpy

Would I like a 95 with too small a tp port and too much soft spring -nah
One with a lightweight hw mod where balance is off and barrel won't hold on target - nah

I haven't shot a new Diana 34EMS version, but the last gen 31/34 T0-6 Dianas with sorted internals are indeed just as nice as a well sorted 'stage 1' 95 imo with their tp just about right from factory as it goes

[HW777]

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 bass 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.

Nowhere near as technical as the pencil method, I've always judged a springer by how far the reticle moves off target in relation to the shot cycle, contrary to what many people think, a fast action springer is better for accuracy than a soft sedate actioned rifle, if you shoot a rifle at it's designed power level this becomes self apparent.

[TopDog]

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.

Hi

It's up to the researcher to do any force diagrams and the ONLY way to solve these issues is to get to the numbers otherwise the argument just goes around in subjective circles. There is NO easy answer to any question of dynamic effect experiences but subjective experiences stand little chance of determining the reason and then giving hope for a solution. This was never more highlighted than when I was doing assessments of piston weight and stroke on 97k actions when I had two (as near as possible) identical actions which were modified one at a time and compared by a panel of the best/most experienced shooters at our club. Each time, the one judged the best was used as the reference for the next test after the next modification suite on the other etc etc etc. Once the difference appeared to be miniscule I did two further assessments without changing anything in either action, just swapped the stocks and the results followed one of the stocks, judged by all to be the nicest! It's all what I have tended to call Shooter Feel Good Factor and it applies to any tool I would suggest; if one likes the look of the tool and it appears to be the one for the job, one will do a good job with it. And, the final variable which has the greatest effect is the Shooter, who's abilities and perceptions are key to this satisfaction!

Oh yes, the sensor in the diagram is an accelerometer from the range I have to conduct whatever tests are required at the time. The main reason for including the diagrams was to show the turning moment when recoil will tend (if the action is unrestricted) to rotate the action about the CoG flipping the muzzle up! Of course, the pellet exits the muzzle in the lunge (surge) phase so would flip down! This diagram is oversimplified since the action CoG will shift forwards during the action cycle as the piston/spring assy travels forwards but let's not overcomplicate things so early on! The main points will be that if the action sits low in the stock, the CoG will be less far from the Action dynamic centreline - so flip will be reduced.

Anyway, will bow out again now before I write a book!

I will however, dig out my 0.177 95k which I sorted some years ago and fitted a 98 stock but do not generally shoot nowadays and see what I feel (subjectively) about it now!

Happy airgunning!

atvb
David

[maximus]

Thanks for the comprehensive reply David. I agree with you that if you want a thing to be good you will cut it more slack mentally. I confess that I am feeling a bit that way about the comparison with the Diana's! I don't think I'll be building any test rigs or doing any guzzinters to work out mathematically why my 95 bucked about more (or appeared to) than my Diana's. My question was born out of frustration at the difficulty of shooting good groups and the difference I noticed in loss of target picture when firing. As said earlier in the thread, accuracy has returned once I changed the main spring. I didn't think the one in it was anything silly but changing it has fixed the issue. It just shows that changing one thing on a springer affects another.