I bought a really nice Mk2 HW77 .177 full length at the bash from a well known gentleman on here.
It had been moth balled since purchase and shot well at the bash with quite a soft feel.
I knew it was gummed up as the safety would not set.
when I got home I stripped it, cleaned the piston and chamber, de-burred the cocking slot.
I had a spare spring and guide from another .22 HW77 that I have. The replacement guide fits the spring nice and snug. It has a shamfered metal baseplate hole that the delron guide fits into.
I ground and polished the washer on both faces and decided to do the same with the back block just in case it might give a little more rotation on firing. Fitted a spring guide made from a can of St Austell Tribute Ale so we were both nicely lubricated. Ground and polished spring ends a smear of moly. Put back together, chronoed and yes just shy of 13 ft lbs. So strip, cut off two coils and finished ends also removed a preload washer and now around 11 - 11.2.
I am really pleased with the accuracy and feel of it. It is quicker now with no twang.
Club meeting tomorrow so it will have good airing!