I'm wondering if anyone has any info on the correct size/spec for the sub 12 Pro Elite mainspring. I've ordered one from a well known distributer but its a good inch shorter than the one that was in there and that one had barely any preload.
What concerns me is that some of the parts diagrams online from the gun spares chaps have parts listed as TX****. I know there will be a lot of similarities, but did the PE sub 12 version share a TX spring/top had and guide?

Any history lessons from people with experience of both rifles ideally.