The 160 FTX in my single experienced expanded pretty well, and held together. I haven't weighed it, but I'd guess 60-70% retention. Shot was maybe 40 yards right on the point of that buck's shoulder.
It's a polymer tipped bulet with a boat tail, but the B/C isn't real high. It'll certainly make it 300 yards but it'll de dropping like a rock, especially when launched at 307 speeds. I haven't played around with the ballistics but wouldn't be comfortable using it way out there without some sort of a turret or dotz, both of which would be pretty awkward on a Win 94.
A leupy 6x36 with dotz may work out OK though. I have a Leupy 2.5x20 Ultralight with the heavy crosshair on mine, and it sure as hell ain't designed for 300 yard shots.
