[is it big enough]

I think it can be done, but it is a marginal application. Personally, I would use nothing less than the .41 Mag with the .44 my prefered for deer.

[Changing rifle sights]

Does anyone know if you can get aftermarket sights to improve those on a M1 Super 90 short barrel with rifle sights (not ghost ring)?

 

If so, where would you find such a critter?

 

Thanks in advance!