Hw99 tuning

[lola]

What's your prefered set up of a hw99 internally? With mine I'm planning a good polish of everything, a vorteck piston seal, sandwell fieldsports spring, and ptfe spring guides. Does this sound good to you guys?

Also would you guys fit a piston sleeve or not? Whats the pros and cons of using a piston sleeve?


Cheers!

[rabbitwrecker]

Just a polish and lube with my two, nothing aftermarket...

[Shed tuner]

.177s are a fraction bouncy, so a longer, softer spring helps. Well, it certainly helped mine
A port tickle may have had the same affect.

They are pretty well setup out of the box.

Oh, and to the 99 fans - HW do have a non gauling articulated cocking lever solution - it's on the HW90

[lola]

Mines a .22 screw cut to 10.5 inches.

What's people's opinions on using a piston sleeve in a 99?....

Use a piston sleeve in them or not? What are the pros and cons?

[tinbum]

Mines a .22 screw cut to 10.5 inches.

What's people's opinions on using a piston sleeve in a 99?....

Use a piston sleeve in them or not? What are the pros and cons?

Cons: It adds mass to the moving parts and can cause issues binding on the spring

Pros: If you use too much grease it'll help stop it migrating and if your guides are a poor fit it'll reduce twang

[Shed tuner]

Pros: If you use too much grease it'll help stop it migrating and if your guides are a poor fit it'll reduce twang

depends on the piston / spring clearance - some will twang even with good fitting guides:
http://www.airgunbbs.com/showthread....Piston-sleeves

[lola]

Thank you... What would I hear and feel if it's binding?

And what problems could extra mass cause?

Cheers!

[Scubashot]

For what it's worth I've just fitted a TbT drop in kit in my wife's HW50. It uses the original spring with a new spring guide and top hat. I made a piston sleeve out of a steel beer can, then deburred, polished and lubed everything.
I took the opportunity to carry out the degalling mods before reassembling.
The gun now cocks sweetly and the twang that accompanied every shot has disappeared completely.
I'm sure that the additional weight of the piston sleeve would be insignificant for most users but it is not supplied with the kit as it is regarded as an optional extra.
A simple and effective upgrade.

[Sallyannsnow]

Chopped the barrel on mine by 4"" and screw cut to fit a nice mod. Tbt drop in kit using standard spring and polish the internals. Fitted a piston sleeve made from shim steel as I figured I might as well.
Shoots really smooth with just a dull thud, very happy with it (.177) but I have to say it was great straight out of the box ! Be warned 99's are very adictive when it comes to fiddling with.

[Shootfish]

For what it's worth I've just fitted a TbT drop in kit in my wife's HW50. It uses the original spring with a new spring guide and top hat. I made a piston sleeve out of a steel beer can, then deburred, polished and lubed everything.

Just to clarify, you used a 'steel' beer can, not an aluminium one?

[Rickenbacker]

Oh, and to the 99 fans - HW do have a non gauling articulated cocking lever solution - it's on the HW90

What?? It's not articulated in the same place, and it has the wrong 'end' on it. Have you been at the sherry?

[Scubashot]

Just to clarify, you used a 'steel' beer can, not an aluminium one?

As there were rust spots starting to appear on some of the cans I was pretty sure that they were steel rather than aluminium. To confirm this I have just checked the remainder of the can with a magnet and it is steel.
In case it is of further interest I put a micrometer on it and came up with 0.003"
This worked very well as it is already curved and rolls neatly for insertion into the piston.
Rather than inflict a long, arduous research program upon you I can tell you that this was a Carling lager can! ;-)
If you are really anal and it matters to you I could weigh a section of appropriate size on my pellet scales - let me know.

[TonyL]

What?? It's not articulated in the same place, and it has the wrong 'end' on it. Have you been at the sherry?

Must admit, Phil, I was thinking the same. But then I've never worked on a '90. Just had a look on the Chambers site and there's that glider piece, BK073. As you say, maybe not articulated in the same place and there's a separate cocking shoe.

But if John's had a play and can confirm it works, that'd be great.

Much work altering anything involved, JB?





And, yes, I have seen it on here in the past that the Carling cans are steel rather than ally.

[vestlenning]

Mine has just seen polish and new lube. I don't mind a little sound and recoil when shooting, it's nice to know that the shot has been fired.