Hw77 piston woes

[yorkiets]

Ok, I thought I'd got a good deal on the latest renovation but I've been well and truly taken for a ride.

Of the many 'issues' I've found, the piston is worn through in the slot where the cocking lever sits against it.

What are my options here? Is it just a case of a new piston?

[Shed tuner]

Ok, I thought I'd got a good deal on the latest renovation but I've been well and truly taken for a ride.

Of the many 'issues' I've found, the piston is worn through in the slot where the cocking lever sits against it.

What are my options here? Is it just a case of a new piston?

can you not just repair with a thick sleave ? Also, I'm not sure it really matters if it's worn thourgh, I mean the lever can't go anywhere (esp with a sleave) ? It's just to stop the piston rotating, right ?

PS I'm no 77 expert, just starting playing with mine, so I may be missing something here !

[yorkiets]

can you not just repair with a thick sleave ? Also, I'm not sure it really matters if it's worn thourgh, I mean the lever can't go anywhere (esp with a sleave) ? It's just to stop the piston rotating, right ?

PS I'm no 77 expert, just starting playing with mine, so I may be missing something here !

Perhaps you're right, Jon. It looks ugly but maybe a tidy up and a sleeve would do the trick.

How about trimming the piston to make it skirt Less? Has anyone done this before?

[Shed tuner]

Perhaps you're right, Jon. It looks ugly but maybe a tidy up and a sleeve would do the trick.

How about trimming the piston to make it skirt Less? Has anyone done this before?

Yes (in an 80), However unless you are going to convert the piston rod and trigger sear to make it a rotating piston setup (like a TX) you'll need the skirt to stop the piston rotating.

[yorkiets]

You're right. It's not worth converting this one.

Tidy up it is, then.

[T 20]

Ok, I thought I'd got a good deal on the latest renovation but I've been well and truly taken for a ride.

Of the many 'issues' I've found, the piston is worn through in the slot where the cocking lever sits against it.

What are my options here? Is it just a case of a new piston?

Having had a relaxing day of detuning with my 30 year old HW77.

The cocking lever just sits in the slot, the only thing it could wear through would be a piston liner.

Are you sure you're not mistaking a steel liner for the piston body ?

Pictures would be good.





All the best Mick

[Captain Bongo]

Are you sure you're not mistaking a steel liner for the piston body ?

I made that mistake with my very first '77. One Boddingtons can and one trip to A&E later the gun was better than ever.

[yorkiets]

Having had a relaxing day of detuning with my 30 year old HW77.

The cocking lever just sits in the slot, the only thing it could wear through would be a piston liner.

Are you sure you're not mistaking a steel liner for the piston body ?

Pictures would be good.





All the best Mick

It's worn through the slot completely mick. The cocking lever is knackered too, the hook had snapped off so perhaps the last owner was pushing the lever upwards to stop it falling out.

[T 20]

It's worn through the slot completely mick. The cocking lever is knackered too, the hook had snapped off so perhaps the last owner was pushing the lever upwards to stop it falling out.

This is what a standard 77 piston looks like without a piston sleeve :-

http://images.nitrosell.com/product_...n-complete.jpg

Now whereabouts has yours worn through ?



All the best Mick

[yorkiets]

This is what a standard 77 piston looks like without a piston sleeve :-

http://images.nitrosell.com/product_...n-complete.jpg

Now whereabouts has yours worn through ?



All the best Mick

Just been out for a closer look and a prod. You're right, it's a well fitted sleeve that's worn through. The piston itself is not bad. It really looked like the slot was milled in but not all the way through. Removed the sleeve now.

It's been a long day, don't judge me too harshly

[T 20]

Just been out for a closer look and a prod. You're right, it's a well fitted sleeve that's worn through. The piston itself is not bad. It really looked like the slot was milled in but not all the way through. Removed the sleeve now.

It's been a long day, don't judge me too harshly

No problem --- just glad you're sorted.



All the best Mick

[Shed tuner]

well, that's easy then

[deejayuu]

Relieved and pleased for you at the same time. At first read thought you meant torn the slot through to skirt.
Visions of someone firing with something between cocking lever and barrel. Like table top!!
Hence sheared cocking lever like this


Here's the "temporary " replacement.


Which probably means it'll never get a new one

Any chance you could give specs. for the spring while it's out please?
Dimensions and rate would be great.

[TonyL]

No problem --- just glad you're sorted.



All the best Mick

As ever, the uber-knowledge and friendly assistance of the BBS to the rescue.

Nice one, Mick.

[T 20]

Any chance you could give specs. for the spring while it's out please?
Dimensions and rate would be great.

I'm using a Walther LGV Spring in my .177" Hw77k, these seem to work very well.

Here's the dimensions :-

http://www.airgunbbs.com/showthread....95#post5864295


If you read through that thread you'll get a few more 77 Spring specs.






All the best Mick