Quote Originally Posted by rapidresponse1 View Post
niko sterling mountmaster it come on a rifle i bought
Had a similar issue with a Mountmaster years back. First one arrived damaged, took a lot of arguments to get it replaced. When it eventually was, the new one behaved like yours. Think I chucked it in a cupboard, probably still there. Funnily enough, had Mountmasters on some s/hand rifles I've bought, & they've been fine.
Can't remember the supplier.