30# recurve will take whitetail buck out to 20yds maxand is very deadly as you can hold it like a compound with your fingers.
secret is you have to have a good heavy arrow for energy and sharp point.

as long as your shots are close,20 yds .

many, manyof kids i grew up with used a 30 # bow.
i dont know what the law is now on that, i think its still 30# is minimum you can use.

as for crossbow, i am not able to help but if i was using light pdbow, i would use heavy arrow and shoot close,like 20 yds.