If it were a 35 Remington (low pressure and 38-ish grains of propellant) maybe 50 fps. But 356 Win is way closer to a 358 win (higher pressure and 46-ish grains of propellant) than a 35 Remington. So I'd guess minimum 100 fps and quite a bit less muzzle blast to boot. You'd be in 358 territory for sure.