Rant!!

[flyingfish]

Bloody springers
Had a nice plink Saturday at LVAGC. Noticed that the 98 started shooting low after a 100 or so shots. TX worked well though. Got home cleaned guns, chrono the 98 650fps. Strange she shot well at the bash.
Chrono the TX. Even worse. Fitted 2 power washers still only just 10ft/lb. Stripped the TX today, can't see anything wrong. Re_assemble 11.25 - 11.17.
The 98 still low over chrono. Sort that tomorrow I hope

Rant over

Pete

[TonyL]

Had you chrono'd them previously, Pete?

[flyingfish]

Yes Tony, TX was around 11.25 & 98 11.4. Pellets from the same batch, so thats ruled out. TX must have wanted some love. Don't know why the 98 is sulking though

Pete

[TORNADOS7]

Bit confusing, what exactly is the issue ?...

[TonyL]

Yes Tony, TX was around 11.25 & 98 11.4. Pellets from the same batch, so thats ruled out. TX must have wanted some love. Don't know why the 98 is sulking though

Pete

The 98 probably just needs a small slice of German sausage to make it happy again, Pete.

What set up is it running? Standard spring and seal and with Nick's guides?

[VALE BOY]

Curiously enough I had a similar situation recently with my HW98 which up until a few months ago was an absolute tack driver. It was firing inconsistently vertical spreads as much as 10" to a foot or so even at ranges down to 20 yards. Initially I thought the scope was to blame but after changing it for a different one it was still shooting similarly. It was only inconsistent in the vertical plane and there were variations in the chrono readings between 10.6 and 11.3 if I remember correctly.
However, down at the recent Boinger Bash, Unframed Dave gave the barrel a clean with the kit that he had and it seems to be back shooting consistently now.. Thanks Dave..
Guid luck wi finding out what's causing yours to shoot the way it's doing.
Atb Graeme

[TonyL]

Maybe, just maybe, with these higher temperatures, heavy use and if the piston seal is slightly on the tight side, the increase in temperature and expansion of the piston seal has created more friction, Pete?

[flyingfish]

I will try pulling the barrel through. Its the short stroked one you shot at the bash Tony.
I think the heat must be involved but why did the TX cure itself?
Pete

[TonyL]

I will try pulling the barrel through. Its the short stroked one you shot at the bash Tony.
I think the heat must be involved but why did the TX cure itself?
Pete

Maybe the strip (and did you lightly lube the piston seal?) helped and is your workshop / subsequent chrono test in cooler conditions?

You never know, a subsequent chrono test in slightly cooler conditions (guessing you were in the blazing sun yesterday and the dark action is operating like a heat sink?) may see power restored without even stripping?

P.S. Can't now remember if it was someone at The Bash, or in some of Jim's writings, saying that the style of seal used in the TX may expand less due to less piston seal material as compared to the HW style?

[flyingfish]

Both short stroked with hw seal. Tested before stripping so a mystery. I think it's something to do with the lube but what?
I am going to trade them for a pcp....

Pete

[TonyL]

I am going to trade them for a pcp....

Pete

Are you suffering from sun stroke, Pete?

[TonyL]

I think it's something to do with the lube but what?


Pete

What lube do you use, Pete?

You'd expect most lubes to get thinner with higher temperatures, so I'm thinking that it will more likely be seal expansion.

[flyingfish]

Just moly based lubes that come with the short stroke kits. Family duties tonight and tomorrow so may have to wait until Thursday to strip the 98

Pete

[averageplinker]

How is the breach seal looking on the 98?
Rich

[Airsporter1st]

Maybe the strip (and did you lightly lube the piston seal?) helped and is your workshop / subsequent chrono test in cooler conditions?

You never know, a subsequent chrono test in slightly cooler conditions (guessing you were in the blazing sun yesterday and the dark action is operating like a heat sink?) may see power restored without even stripping?

P.S. Can't now remember if it was someone at The Bash, or in some of Jim's writings, saying that the style of seal used in the TX may expand less due to less piston seal material as compared to the HW style?

How much dies leather vary with temperature, I wonder? Makes me think that the early designers had it right first time.