Quote Originally Posted by bigtoe01 View Post
The original fwb sport has 28mm bore, 77mm stroke, the Diana 280 which is in essence a sport copy has the same bore and stroke. The fwb has a much shorter transfer port however and is more efficient..which makes it tune that little easier and is why it was more popular (and still is)
Any new fwb sport would do well to copy the old bore and stroke, but improve the trigger (which was its weak spot) and the stock.

To get it down to 7.5J i have a feeling fwb will have a piston running around 65mm stroke, maybe 70 tops, as long as the piston uses a latch rod this can be altered to push it back up to 77mm or so, however in .22 all that would be needed at 65mm stroke is a stiffer spring as long as the transfer port is short enough to get 15.5J, it may even be doable in .177 also...it all depends on the TP.
My guess is that they won't use a latch rod because that's what most other manufacturers use and they want to be different, it'll probably be like the old one and use the outside of the piston, which makes it more difficult to change stroke.

Cheers

John