Setting a projectile's rotation?

Hi, I'm trying to create a gun that fires cylinder-shaped projectiles. I want the projectiles to be rotated in a way that the ends are facing downwards and not side to side.

player = game.Players.LocalPlayer
weapon = script.Parent
mouse = player:GetMouse()
function shoot()
    local laser = Instance.new("Part", workspace)
    laser.Shape = "Cylinder"
    laser.CanCollide = false
    laser.Size = Vector3.new()
    laser.BottomSurface = "Smooth"
    laser.BackSurface = "Smooth"
    laser.FrontSurface = "Smooth"
    laser.LeftSurface = "Smooth"
    laser.RightSurface = "Smooth"
    laser.TopSurface = "Smooth"
    laser.Rotation = Vector3.new( 0, 0, 90)
    laser.CFrame = weapon.Handle.CFrame
    laser.CFrame = CFrame.new(laser.Position,mouse.Hit.p)
    v = Instance.new("BodyVelocity", laser)
    v.Velocity = laser.CFrame.lookVector *90
    v.MaxForce = Vector3.new(math.huge, math.huge, math.huge)
end
weapon.Activated:connect(shoot)

Even though I set the projectile's rotation, the rotation is still way off when it's fired.