Hi,
I have just received 140% buffer spring and buffer from airsoft surgeon, effectively, the spring is very hard, cocking make the M4 like a bolt VSR10.. I think i gonna just keep the buffer and reinstall the original spring.
I have too a POM nozzle, I had to said I'm very unhappy with it, a lot of casting flash are present in the interior and interfere with the original WA internals (it finally have broke the extremity of the nozzle, the 3 faces shaped lug a the extremity.) Be wary of this piece if you don't want to play with sandpaper...
Sorry for my bad english
Seb