You might have to shorten it.
If you ever get a QB57 you'll never look at your wife again........well, maybe it's not that pretty. I got the .22 cal. and did my own tuning. Kept same spring, just added a top washer. Out of the box 530.fps and after tune 585fps. It is quiet, silk smooth and very accurate with RWS Pointed out to 25 yards. Don't even hesitate, get one.
And another Gene inspired build.FUN!!!!http://www.gatewaytoairguns.com/airguns/index.php/topic,24911.0.html
I carved and drilled some baltic birch plywood that I glued together and the fore stock as well although it 's not a very original design. It was a royal pain to get the fore stock to work and now I wish I had done the whole thing in one piece and then figure out some sort of clamping scope mount as I have seen others do. I cut the majority of the cavity with a table saw and a jig set diagonal to the blade, then pass the stock over the blade raising a bit each pass to the desired depth and finish off with hand tools.