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Old 4th September 2016, 07:48 PM
hmangphilly hmangphilly is offline
Senior Member
Join Date: Nov 2013
Location: wimborne
Posts: 587

Originally Posted by Nick G View Post
Went to the springer bash yesterday, with 21, 22, 23, 24, and 25mm, set ups , a lot of people shot them and the general consensus was the 21mm was the best , ie shot feel, and cycle speed , very low sight picture movement, though this tune is about as far as you can go it makes 10.8 in the carbine action, any more spring and it diesels , big time ( burns all the lube out in one shot , it is very consistent over the chrono. at the moment it is skirtless but I have a problem with the piston going tight after around 100 shots , so I have sourced a different spring so I can run a full piston and therefore use a longer spring ,so hopefully it should make the power , fingers crossed , if I can sort this I think its probably the best tune I have come up with to date , very easy to cock , and hardly any sight picture movement.
O rings definitely the way to go for consistency, but the groove sizeing is crucial,for longevity, and making the power.
does the piston loosen off again nick ?

or does it tighten up after 100 shots and stay tight ?

i think i'm asking whether the tightness is heat related ?

rob and i were measuring ally versus steel pistons for expansion .

so you're looking for a 18 -19 mm od spring ?
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