Taming the HW80 my way

[TonyL]

we all know how Venom did it with the Lazerglided 80 & it's well known Bigtoe01 did a similar thing by sleeving the 80's 30mm cylider down to 25mm, he went that extra mile & fitted a Walther LGV rotating piston & altered the trigger latch sear to accommodate the Walther piston rod.

TonyL has always said how he liked my short stroke modified 80 ever since shooting it at last years springer bash,




How does it shoot, well the stroke on this version is only 60mm, 12fpe is no problem at all, makes it with loads to spare. It shoots like a dream, so quiet too, I'm amazed myself with this one so lord only knows what TonyL would think because it's miles better than when he last shot it. Quick but not snappy, no lag or hint of laziness. Is it as good as a 80 Lazerglide? No! it's so much better it's in a bifferent league, truly!

OK so it's .22 what would it be like in .177 I here you ask, well I can tell you, a quick route round to find my 95k with the 310 barrel, a quick change over a tin of JSB Exact over the chrono 10fpe & stunning to shoot. I have a HW55T I shot bell target with last week, the 80 is quieter, smoother, easier to cock & has miles less recoil.......am I happy I'll say!!

Let me tell you, forget upping the power on a HW55.........Detune & tame an 80, I promise you won't regret it, it's the way to go.

Is it finished NO!

This sounds ABSOLUTELY AWESOME, Dave.

I'm frothing at the mouth already!!

I know I'm not the first...many, many springer fans will have debated for years as to which would be the best way to go......narrow bore / longer stroke vs big bore / mega short stroke.

Much of the more recent thinking has pointed more towards the smaller bore option being the favoured option, with lighter piston weight and the fact that pellet release pressure is achieved whilst the piston is further from the cylinder end wall, supposedly giving more manageable surge characteristics.

But THIS is very encouraging. Yes, your short stroke 80 I tried last year was beautiful. Okay, we weren't doing clinical accuracy testing, but I have no reason to suppose that it would not be anything other than very accurate and forgiving.

And you say that this latest project results in an even better firing cycle. FANTASTIC!

This could finally lead to the 80 re-establishing itself as a firm favourite amongst UK shooters.

I know I asked last year if you'd consider making a short stroke piston commercially available.....If this thing works as well as it should, and judging by your findings so far, it does, this could be a very simple drop-in affair, so easy for those with only basic skills to completely transform their rifles at home; something that many couldn't undertake a reduced cylinder conversion without more tooling or expertise. And I really love the idea of the longer rod, as I've mentioned previously, so you don't get that "dead" movement on initial barrel opening.

Bring back the mighty 80. A big, solid, heavyweight of a thing. Solidly engineered to last a lifetime. Loads of weight to settle the aim and soak up the slight recoil.

With you mentioning the performance vs the 55....... Just think how sweet you could make one with an even longer rod, tiny stroke, set up to produce 6 or 7 ft.lbs!!!!


I WANT ONE!!!! Please!

[bigtoe01]

same basic make up as my LGV piston with a short stroke 30mm nose and the LGV piston weighs less....

Not as shiny though

You have to remove around 8mm off the stroke by adding to the nose minimum to allow the new style cocking shoe to be used, you can go down to 55mm stroke if you do the rod and the nose and still see 11+fpe at 30mm especially in .22

[wonky donky]

same basic make up as my LGV piston with a short stroke 30mm nose and the LGV piston weighs less....

Not as shiny though No Tony its not got a short stroke nose.

You have to remove around 8mm off the stroke by adding to the nose minimum to allow the new style cocking shoe to be used, you can go down to 55mm stroke if you do the rod and the nose and still see 11+fpe at 30mm especially in .22

No I just made the body of the piston longer! If I had used a short stroke nose the piston would have been lighter but I'm not entirely sure I want it much lighter tbh

There's always more ways than one!

[bigtoe01]

aye i know BUT you have increased weight, I did an LGV piston here for an 80 with 30mm nose that weighed 230g 70mm stroke, 50g lighter than where you are at... which means you can tune the piston weight now with steel or brass tophat etc or use acetal to keep the weight down.


get drilling some holes or thin it down some more.

Alloy body, threaded skirt, steel bearing band on the back loctited on (hardened steel) may be the best bet

[wonky donky]

aye i know BUT you have increased weight, I did an LGV piston here for an 80 with 30mm nose that weighed 230g 70mm stroke, 50g lighter than where you are at... which means you can tune the piston weight now with steel or brass tophat etc or use acetal to keep the weight down.


get drilling some holes or thin it down some more.

Alloy body, threaded skirt, steel bearing band on the back loctited on (hardened steel) may be the best bet

Absolutely no chance! Don't forget I'm at 60mm stroke not 70mm. my first mod was at 68mm! I'm heading for 50mm & I feel you can go to light. there comes a time when you get diminishing returns & I feel it's far sooner than the theories may suggest.

Anyway I have not increased weight the original piston was well over 300gms 340ish iirc?

The lighter the piston the more spring/pre-load, I know this you know it & others on here have been finding out....I put a thread on here some time ago HOW MUCH PRE-LOAD IS TOO MUCH but deleted it because it attracted mostly uneducated responses.

Untill I have more of my own data it remains as is...anyway you haven't shot it! I had a chap here today with his shooting mate from Liverpoll trying it & they were absolutely blown away with how it shot.......the one lad has had rifles tuned at all the best tuning houses as well!

No nothing radical, a bit at a time will do!

[flatrajectory]

At the end Dave's first post he says he is happy ( that's a first), then goes on to say ...." is it finished, No..."
That proves that Dave is not actually happy. Dave is never happy with his tunes.....even when I shoot one of his tuned rifles ,that may have had 20 hours work on it,and go "wow"..... worries that it isn't good enough.
This is why his tuning work is so outstanding and worth every penny. His quest for perfection is never ending,, and for that WE should be grateful. Wonky and Bigtoe are always searching for perfection but because of their mindset will never find it.
They are true airgun tuning pioneers, ' boldly going where no man has gone before'.
Just don't overdo it mate.....oh, and yes you do need to get out more.!
atb,
Pete.

[Shed tuner]

The lighter the piston the more spring/pre-load, I know this you know it & others on here have been finding out....I put a thread on here some time ago HOW MUCH PRE-LOAD IS TOO MUCH but deleted it because it attracted mostly uneducated responses.

I'm rather interested in this too... for me personally, so long as the piston isn't slamming, the only way you can have too much preload is:
i) the gun in too hard to cock
ii) components are put under excessive stress
iii) the spring itself is under too much stress

Personally, I like lots of preload... but practically, most of my guns end up shooting nice in the 40-70mm range... probably about 50-60 kg preload force max, most are more like 15-30 kg (and around 50mm)

[bigtoe01]

at 60mm or so you have turned the hw80 into a hw35 with a short transfer port...interesting fact