Diana mod 45 t01

[jonnyone]

Dave, I am interested that you say the piston seal is PTFE as this material is soft and malleable and would change shape when hitting the end of the cylinder. Most piston seals are polyurethane which is tough and hard wearing.People have experimented with PTFE seals and find they extrude into the transfer port. I think the only area you could use PTFE is in a piston ring seal where there is no impact, so is your material a harder compound mix ? Would be interesting as urethane is not the easiest to turn complex shapes on the lathe.

Baz

Hiya Baz,
The heads on both '45s are plastic (they are 110% not leather). These heads were certainly marketed and bought as being of ptfe. I am no expert on this so must assume they are. They are not the only guns I have them on. I have lost track all together but think I also have them on a couple of Anschutz 335s, an Original 50, a 50T01. I think the only gun that ptfe didnt work that well on was an early 35- but I was warned the business end of the compression tube was ever so slightly constricted on these. As you say ptfe is pretty unforgiving in that sense. I can only speak from experience and all the guns I have fitted these heads to work fine. I have stripped one or two over the years after some amount of shooting and have not noticed any degree of distortion.
I would say though that if I was engineering minded I would turn a steel piston head converter to revert to the later Diana standard piston heads. I know many would say that is moving away from originality but I have had a couple of instances where leather heads have expanded and sapped power dreadfully. I know power isnt everything- but if we have been given 12 ft llbs then I want to use it. Then again I dont punch holes in paper or shoot HFT. I recall on Anschutz 335 I purchased had a new leather head fitted by the previous owner and it had been soaked in oil and had siezed the gun solid. Plastic (ptfe I assume) soon had that one shooting sweet

Sorry for the thread hijack Nickos. I hope you get this '45 punchy and accurate

As I say- I am not an engineer- I just speak as I find and from my experience.

Dave

[Nickos]

Check breech seal ,some sold to suit are pants and don't . I can p m correct size tomoz.
My guess either breech or main seal is damaged.
Did you debure slots on cylinder ?.
Was seal cut prior to re install.
Check crono too.

Strange to drop 2 ft lb

When I dismantled it, the spring was bone dry, but it was greased up around the piston seal and some had gone in front!maybe that accounted for the extra power?
The piston seal doesn't look 100%, a little nicked in places...hence why I'd prefer a complete kit.
I'm sulking at the mo with it, it's been wiped down and put in a dark place.

[original45]

Well seal should be as 34/36/38 rws blue type 28mm ,latter 45 were such .
I can't give you correct spring length for the latter 45 as I never recorded mine when re lubing .
How much preload did it have on re fitting ? 2"pluss ?
Unless spring was broken or left cocked months or longer I can't imagine why it is only doing 6 .
And only that with extra preload and re lube

[Nickos]

Yes I'm left scratching my head a bit..
I phoned steve pope and he's going to make a kit for me, I'm going to send him the piston and spring guide, so hopefully this should 'pep' up the old girl.
I really should put up a couple of pics I'm still trying to work out this new fangled photobucket thingy!

[original45]

Lol I can't do photo either crap with I.t .
Steve's kit will be good but most likely will increase the cocking effort.
Should def shot nice with a kit Steve's stuff is top quality .

I do prefer the rws blue seals by far longer lasting and self lubricating .

Hopefully not too long to wait until it's sweet as a nut

[PCPShooter]

Best solution you've gone for
V Mach did two 45 s for me Leather seal new spring set, shot great Cocking effortbin 22 is OK