I just built my Hy-Score and thought the same thing when I chronoed it, thing is atleast mine gives 350fps with 7gr Gecos, thats only just over 1fpe
Sadly the wife has seen fit to stop gun time as she promised and Ive not experimented further
It is consistent, the spread is between 348 and 352, and the geco pellets are very tight in the breech, so tried seating them further into the rifling, it didnt increase the fps at all, even so I did think that they were supposed to produce atleast a 100fps more than this
I shot some testing shots into a couple of layers of A4 on my pellet catcher and on several occasions it barely broke the top 2 layers
When I'm allowed I'll give fitting some pre load washers in and see if that produces any better results.
Short of that I hope Mr Chambers has at least 2 sets of springs in stock next week
Sean