Why is the HW95 so bouncy??

[robs5230]

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.

Hi Tony.
Yep. More than 1 way of skinning a cat to be sure.
In fact the best shooting TX I ever had, used a HW mainspring.

This 95 has a reflex slimtech style silencer fitted.
Its a little chubby in my mind at 25mm OD, and before actually finding out just how well the 95 shot, I'd planned on turning the OD of the slimtech down from 25 to 20mm (then getting it reblued).
I have a sneaky feeling that the extra weight that the slimtech currently carries, is part of the reason its shooting so well. I need to field test it as soon as I can and if its anything less than perfect, the slimtech will get turned down, and I'll definitely have the vmach spring out and go my normal route.

[TonyL]

Hi Tony.
Yep. More than 1 way of skinning a cat to be sure.
In fact the best shooting TX I ever had, used a HW mainspring.

This 95 has a reflex slimtech style silencer fitted.
Its a little chubby in my mind at 25mm OD, and before actually finding out just how well the 95 shot, I'd planned on turning the OD of the slimtech down from 25 to 20mm (then getting it reblued).
I have a sneaky feeling that the extra weight that the slimtech currently carries, is part of the reason its shooting so well. I need to field test it as soon as I can and if its anything less than perfect, the slimtech will get turned down, and I'll definitely have the vmach spring out and go my normal route.

Re the spring......excellent. Anglo-German collaboration at its best.. Although, I suppose any spring from any donor, as long as the quality is high and is of the correct size / specification can be successfully re-homed.

Re the silencer, yep, one could only agree that it will look better once slimmed down. But if it works well.....

Jim once showed detail in one of his excellent articles of "fine tuning" barrel characteristics / weight distribution by experimenting with movable weights. Different weights which could then be located at different positions on the barrel and the results compared. Be great to have the time and facilities (and understanding partner!) to be able to have a play with this.

[TonyL]

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! ]

Have you fully recovered now, Max?

[maximus]

Have you fully recovered now, Max?

Just about! Might have a pop with my 34K this afternoon, bit of a breeze but will see how we go!

[Reevo17]

How’s the 95 going?

On my 98 (.22) it was running hot.... little preload so I fitted a short stroke extension. This gave it some more preload and dropped the power to dead on 12. Shot fine but had a sight picture jump.

Took a coil off, now 560fps with Hades, 11ftlb - shoots a dream! Usual springer movement but sight pictures stays dead true!

Worth a try!

[maximus]

How’s the 95 going?

On my 98 (.22) it was running hot.... little preload so I fitted a short stroke extension. This gave it some more preload and dropped the power to dead on 12. Shot fine but had a sight picture jump.

Took a coil off, now 560fps with Hades, 11ftlb - shoots a dream! Usual springer movement but sight pictures stays dead true!

Worth a try!

Hi Reevo, happy with it now I swapped out the spring for a standard spring from Sportswaffen Schneider. With 50mm of pre-load this has given a nice shot cycle and accuracy is great with JSB 4.52 8.44 grain. With the previous spring it wouldn't shoot any JSB pellet very well. Just shows what affect different spring characteristics have on how a springer performs.

[Reevo17]

Nicely done and a nice bit of research learnings as well!

It’s a dark art balancing recoil, piston bounce, surge with the right pellet being released in the cycle!

Nailed it

[TonyL]

It's all in the spring, peeps.

Did you manage to squeeze any playtime in yesterday, Max?

[maximus]

It's all in the spring, peeps.

Did you manage to squeeze any playtime in yesterday, Max?

As it happened Tony, yes I did! First was my Diana 34K, the one with the plain stock which I actually really like the look of due to its simple uncluttered lines. I always had this gun down as being best with FTT but was struggling with my new tin. It does seem to prefer larger dia pellets, most JSB being slack in the bore. Anyway, went round my pellet selection again and found superdomes excellent in it, shot a great group at 30m. Next up was my long barrelled 34. The spring was buzzing a bit on this when I did my group test so decided to strip down and check it out. It only has about 25mm pre load and the guide was a good snug fit so i suspected it was bouncing a bit. Decided to add one steel washer in the piston and see what happens. Again went through the pellet selection this time sticking to JSB offerings as the barrel has never had anything else in it and has always done well with them. Best ones were FAP, fantastic group at 25 yards so have left it the as was running out of light. Need to chrono today to check all is above board. There was still some minor twang but not bad.

[TonyL]

Excellent and thanks for sharing.

Re the slightly twangy one, I suppose you're already using the pellets least likely to promote bounce, so no room to move there. As you suggest, subject to chrono figures, if there's a little wriggle room for a little more preload, that would be handy. Does it have a piston sleeve already, or sufficient clearance for one? If none of the above is plausible, a little bit of twang isn't the end of the world. When twang is an indicator of something untoward internally then, yes, it's good to address it. But I'd doubt that that would be the case with any of your rifles. I suppose if it really niggled at you, longer term, I guess changing the spring may help......bearing in mind the transformation with the 95.

Again, thanks for sharing.

[maximus]

Excellent and thanks for sharing.

Re the slightly twangy one, I suppose you're already using the pellets least likely to promote bounce, so no room to move there. As you suggest, subject to chrono figures, if there's a little wriggle room for a little more preload, that would be handy. Does it have a piston sleeve already, or sufficient clearance for one? If none of the above is plausible, a little bit of twang isn't the end of the world. When twang is an indicator of something untoward internally then, yes, it's good to address it. But I'd doubt that that would be the case with any of your rifles. I suppose if it really niggled at you, longer term, I guess changing the spring may help......bearing in mind the transformation with the 95.

Again, thanks for sharing.

When I chrono'd it I found that it needed stripping again! So I have spent a good while this afternoon alternating preload by various means. Ended up removing the steel washer from the piston and add packers on the guide to end up with 830fps with the FAP which is perfect and accuracy still great. At one point the velocity was lower and accuracy went right out the window! Then it was on to my short stroked 80, which while shot nice groups it was really loud. I put the spring from the 95 in this to see what it would be like. I have had to add a lot of packing and there must be 60mm pre load at least to get it to 827fps with FAP but it is now much pleasanter to shoot. Could do with the same spring with a few more coils so I can lose the packing really but it will do for now.

[Drew451]

This is one of the great BBS threads. Over the last week I have shot my 95 based 85K against my 1991 D38 on a number of occasions after work. This 38, bought of here not so long ago is way ahead of the 85 everywhere. Its not a like for like comparison as the 38 is the usual full length barrel in .177 and the 85 is in .22 with a carbined berrel wirh open sights.
Putting accuracy aside for the moment, the 38 shoots so sweetly with very mild manners and totally linear rearward recoil. It just pushes backwards slightly and with no discernible muzzle flip. The 85 doesn't just lift at the muzzle- the rifle recoils rearwards and upwards along its fulll length. It neither resonates, or exhibits hard slam or piston bounce to be honest and in isolation its fine, if average. But the 38 totally wipes the floor with it easily.
Both bought 2nd hand and therefore I dont know if both are completely standard. The 38 feels standard, and both have no marks/wear on fixings and woodwork and both feel tight and little used.

[TonyL]

When I chrono'd it I found that it needed stripping again! So I have spent a good while this afternoon alternating preload by various means. Ended up removing the steel washer from the piston and add packers on the guide to end up with 830fps with the FAP which is perfect and accuracy still great. At one point the velocity was lower and accuracy went right out the window! Then it was on to my short stroked 80, which while shot nice groups it was really loud. I put the spring from the 95 in this to see what it would be like. I have had to add a lot of packing and there must be 60mm pre load at least to get it to 827fps with FAP but it is now much pleasanter to shoot. Could do with the same spring with a few more coils so I can lose the packing really but it will do for now.

Excellent results, Mr Max.

Just a thought for the longer term re springs for the 80 - if you were to have a look on the Mainspring Data Thread, maybe a 77 spring, one for the various 25mm Gamo models (like the Whisper / Varmint), or one of the thinner wired Titans may do the trick?

[TonyL]

This is one of the great BBS threads. Over the last week I have shot my 95 based 85K against my 1991 D38 on a number of occasions after work. This 38, bought of here not so long ago is way ahead of the 85 everywhere. Its not a like for like comparison as the 38 is the usual full length barrel in .177 and the 85 is in .22 with a carbined berrel wirh open sights.
Putting accuracy aside for the moment, the 38 shoots so sweetly with very mild manners and totally linear rearward recoil. It just pushes backwards slightly and with no discernible muzzle flip. The 85 doesn't just lift at the muzzle- the rifle recoils rearwards and upwards along its fulll length. It neither resonates, or exhibits hard slam or piston bounce to be honest and in isolation its fine, if average. But the 38 totally wipes the floor with it easily.
Both bought 2nd hand and therefore I dont know if both are completely standard. The 38 feels standard, and both have no marks/wear on fixings and woodwork and both feel tight and little used.

It certainly is proving to be one of the most enduring and epic threads, Drew. Very enjoyable. I bet Max didn't realise what a monster he was set to unleash!

Very odd re your 85/95. What scope is fitted? Might be worth an exploratory look-see?

[Drew451]

It certainly is proving to be one of the most enduring and epic threads, Drew. Very enjoyable. I bet Max didn't realise what a monster he was set to unleash!

Very odd re your 85/95. What scope is fitted? Might be worth an exploratory look-see?

Evening Tony. The 85 is fitted with a Hawke Vantage 3-9×40 that it came with and the 2 piece Sportmatch mounts are very stable. . It was shooting .22 RWS Meisterkugelen that you put me onto from the Sheffield place and they are the best pellets I have shot out to 25m.
The 38 wore a Diana diopter sight until Friday aftenoon when I put an old Tasco 1.75-5x40 on it. Interesting how a scope alters the balance and affects recoil characteristics. I put H&N FTTs through it. Typically very tight in the bore but they were great in it.