OLD OLD OLD 0.22 HW50S MK1 what FPE?

[ora8i]

this is an old one:- leather washer/no safety and I think receiver tube has a slightly smaller ID than the newer model and the end block screws on.

After a full service and a new spring about 1" longer than the one I took out I'm getting a miserable 380FPS What should I be getting?

There just isn't a lot of swept volume to work with so I'm struggling.

Relevant work done:-

• Soaked the leather washer in Neats Foot oil, it was in good condition.
• The inside of the receiver was unmarked so I only polished it very lightly.
• Buttoned the piston.
• Replaced the steel disk behind the washer with a Delrin one.
• Put hardened steel washers under each end of the spring.

I could add weight to the piston but the firing cycle is pleasant and I'd prefer to keep it that way.


Regards Ora

[ora8i]

up we go bump bump

[premierpistol]

I was always led to believe the 50s was typically low powered but as it had a smooth cocking and firing action they were accepted like that.

I know of people altering the pistons on a 77 to gain more swept volume so it may be possible to do that on a 50, I've had a couple of 35's with the dreaded 'leak in the front block brazing' problem and just had to live with them being low on power. As they say, power isnt everything, consistency is far better and accuracy is much better.

Just my pennies worth

PAUL

[ora8i]

Thanks Paul.

checking it would take the same Maccari seal as the R7/HW30 and the HW website rates a 0.22 HW30 at 130ms about 390-400 fps?

Ora

[T 20]

I'm pretty sure Jim Tyler had one of these tuned by Venom which was very close to 12ftlbs.

All the best Mick

[coburn]

My 55 (same internals etc) is fitted with a 50 spring and gets around 9ftlbs in .177. Most .22 50's should easily get the same.

[ora8i]

That's interesting when I said I fitted a new spring it was actually one from the parts bin. It's a good fit but I have no idea what it was for so I could be that I’ll have to invest.


Ora

[coburn]

You haven't mentioned the breech seal, I'd replace that with a modern synthetic one if its leather and perhaps get T Robb to knock you up a PTFE piston seal.

[ora8i]

The breach seal is synthetic

Ora

[uk litehammer]

You haven't mentioned the breech seal, I'd replace that with a modern synthetic one if its leather and perhaps get T Robb to knock you up a PTFE piston seal.

Bonnie & Clyde on here is making PTFE seals himself now. He may well have a nice spring for it too.

[Mike95]

You might have the dreaded "tapered cylinder". I have encountered this on a Meteor and whatever I did made no difference! I suppose the transfer port is not blocked?

Mike95