Hello Steve;
As far as recoil, the No.1 in .577 is a real bruiser
to shoot. I have one. Mine weighs 10lb. 8 oz. it has two
mercury reducers in the butt and about the largest barrel
you can spin on without serious rework to the front metal.
It is, as Marrakai said, just not enough weight for full
power loads with a 750 gr. bullet. I started off shooting
750 gr at 2100FPS and am now wimping out to where I use
the 650 Woodleigh at 2000. Next time I will probably drop
that to 1800 or so. A 750 gr. at NE speeds will really get
your attention. I find that the best way to deal with the
recoil is to let the people who ask "can I try it?" shoot
it and I just watch.
Good luck with this project.
Raff