Anschutz 335 - a candidate for piston seal conversion?

[evert]

I'd be sleeving that down after fitting a synthetic piston seal, what is the piston stroke of the 335 ?

I should have measured the stroke... will do at next disassembly.

The gun is now shooting Geco 7grs at 660-670 with Maccaris 28mm seal on a steel dovetail. Still feels slammy.
All the seals and piston fronts I have fit in this gun so far have been marked by the end wall of the comp. chamber after only a little shooting, so it is clear that the port volume must go down.

The spring in this 7.5joule gun is quite soft, its a relatively thin wire (approx 2.5mm?) and has a coil diameter of about 13.5mm's.

Anyone know the dimensions of the springs they are using for the 10-11fpe setups?

[averageplinker]

By coil diameter of 13.5mm are you referring the internal diameter of the spring?

PS Sportwaffen Schneider list the export spring for these as 3.4mm wire, 21.4mm OD, 14.6mm ID and 225mm long
PPS I would love to know how many coils your spring has as I have a project 335 which I am toying with reducing the power.

[evert]

By coil diameter of 13.5mm are you referring the internal diameter of the spring?

PS Sportwaffen Schneider list the export spring for these as 3.4mm wire, 21.4mm OD, 14.6mm ID and 225mm long
PPS I would love to know how many coils your spring has as I have a project 335 which I am toying with reducing the power.

Yes, Internal Diameter, sorry for my clumsy writing.

Thanks for the info, 3.4mm is a hefty wire!

I'll get some proper measurements the next time I open the gun(friday hopefully).

[averageplinker]

The wire does seem beefy!

[weebster]

If the issue is really down to the Mk1s bulging where they were stamped honing probably won't work?

Not just the mk1's...mine has it and its the mk2.

[T 20]

Anyone know the dimensions of the springs they are using for the 10-11fpe setups?

Here's the only reference I can find to the 12 ftlb Spring :-

http://www.airgunbbs.com/showthread....83#post5864483

[evert]

The guns must be completely awful with the heavy spring?
Or does the heavy spring create more aggressive dieseling that softens piston slam?

[T 20]

The guns must be completely awful with the heavy spring?
Or does the heavy spring create more aggressive dieseling that softens piston slam?

When converting from leather seal to synthetic I normally find a big change in firing characteristics using the same Spring.

There seems to be a few theories about this, such as leather sealed Pistons relying on a small detonation of oil to produce power whereas the synthetic sealed piston doesn't.

Whatever the truth is, whenever I convert leather sealed Pistons to O ring or synthetic seal I've nearly always had to sleeve the transfer port down to regain a nice firing cycle --- the exceptions being Airsporters MK1 and MK2 and leather sealed HW35s with the smaller transfer port.




All the best Mick

[averageplinker]

Not just the mk1's...mine has it and its the mk2.

Eek, I had better run a straight edge over my MK2 project rifle!

[evert]

Stroke: ca 74mm, a bit difficult to measure. Can probably be stroked 3-5mm if one relieves the cocking groove in the piston.

The 7,5joule spring measures 2,9mm wire, 14,6mm coil ID, 33coils counting the ground endcoils.

Made a brass TP sleeve, to 3mm. Less slammy, but the velocity is the same with the 7grs Geco.

Tested 7.33grs JSB, and the consistency is amazing; extreme spread of 6fps, 674-680fps.

Perhaps the spring is the limiting factor now?

[averageplinker]

Stroke: ca 74mm, a bit difficult to measure. Can probably be stroked 3-5mm if one relieves the cocking groove in the piston.

The 7,5joule spring measures 2,9mm wire, 14,6mm coil ID, 33coils counting the ground endcoils.

Made a brass TP sleeve, to 3mm. Less slammy, but the velocity is the same with the 7grs Geco.

Tested 7.33grs JSB, and the consistency is amazing; extreme spread of 6fps, 674-680fps.

Perhaps the spring is the limiting factor now?

Interesting; so if the export spring sold by Sportwaffen Schneider is genuine anschutz and so is the one you have removed the main difference appears to be 0.5mm on the spring wire.

[evert]

I have no reason to think the spring is unoriginal.

How can we know if the sportwaffen springs are original or not? Do Anschutz still make them?

[averageplinker]

I guess an enquiry could be made to ask them. I suspect it is.

[thisisdonald]

Interesting thread... following. I've just put my name against 2 anschutz 335 magnum in .177, both in need of some cleaning up, but both in full original working order. I really like the way the gun handles. Very pointable.

[I. J.]

Interesting thread... following. I've just put my name against 2 anschutz 335 magnum in .177, both in need of some cleaning up, but both in full original working order. I really like the way the gun handles. Very pointable.

I have to ask. What is the difference between a '335 and a '335 Magnum (and please dont say £50 ).
Ive got a BSA Super Star 'Magnum' and apart from the word Magnum on the action I cannot find any differences.

ATB
Ian