Could do with a spring as I used the one from this to complete an Australianicon one. Bought the mount for it, that fits on the AR15 then sold my AR15... just had enough of straight pull, excellent rifle though in M4 spec just a ball ache coking it all the time and was fussy on ammo.

Thats why I wouldn't go for one of the straight pull L1A1's that are about, unless I could get the bits to complete the .22 conversion kit (have the mags and box)