Should be helpful:

https://www.youtube.com/watch?v=CF2UyX9Ca3g

...I followed instructions for install putting spacer into the piston, ...correctly lubricating... ...Now piston spacer is stuck in the piston. ... ... if someone can suggest a workable solution to getting the spacer out of the piston,... Most of the time the spacer gets hold up in the piston just ...

...You'd be welcome to visit me at my home in Lincolnshire where... Hi Simon, a tempting proposal though a little bit difficult due to my location in Austria. Anyway thanks for your information. Interesting that you prefer such a low magnification as most shooters would go higher so I think. I had ...

IMHO - yes

Hi Pianoman,

how about some pictures of your 35m-groupings and information about which and how scopes used?!

So you're running a Vortek O-ring kit producing 11,8 fpe. IMHO the O-ring kit does a better job in HPO-systems. So you could get a slight power increase if changing to the genuine AA piston seal you ordered. My resizing referred to the Vortec VAC piston seal. TbT shows three different kits. Two of t...

You didn't mention what's the power output now. I've tried different kits (V-Mach, TinBum, Vortek) in several AGs (HW, AA TX, Diana 34). For me Vortek is the best. To my experience Vortek VAC-seals are a little bit oversized and need some resizing or about 1k+ shots to settle in. So you could try to...

As there is a lot of spring load on relatively small surfaces and pure metal-to-metal contact the use of some MoS2-paste is a must for me.
Never had a problem so far.

Mine is a Mk3 - piston weight 220 grams

After use and in between I give my AGs a nice wipe over with a cotton cloth with some Ballistol oil on.
Very nice for metal and wood stocks too.
Same oil on a cotton patch followed by some dry ones for an occasionally barrel pull-through too.