Custom fwb 300s spring - 260 m/s

[hagonzal]

Hi all,

I just found this page advertising a custom spring for the 300s. They claim that the spring provides 260 meters/second at 16 joules (~11.8 ft/lbs):

http://www.waffencenter-gotha.de/shop/S ... :1109.html

Anyone familiar with this spring?
Does the muzzle energy sound a bit too high for a 300s?

Thanks