p90 compression/airseal issues

[private parts]

Just fitted a m100 spring in my p90, aswell as new piston, Ultimate cylinder head and dream army nozzle.
Gun is chrono'ing under 300fps every shot, ive tested hop and its completely Airtight, and tested compression of piston in cylinder and it seemed good.
Question is, there was 2 o rings with the dream army nozzle, i only fitted 1 , but should i match the nozzle to the cylinder head? so do i buy a ultimate nozzle?

Or.

Am i expecting too much? gun has madbull python tightbore and madbull rubber, but cylinder is ported

[StuartL]

Re: p90 compression/airseal issues

Return to original parts and re-chrono. Then replace each part one at a time (where possible) and see what happens.

[badger906]

is the air nozzle tapered at the end? as i had issues with my thompson (still version 6) using a no tapered one. i placed a systema v6 nozzle in and has been great. i personally think the o ringed ones just adds another variable to go wrong.

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[private parts]

My old nozzle was FUBAR, il try a systema 1 cheers