MY UNCLE HAS BEEN USING A 20 FOR THE LAST 2 YEARS, IT WILL PUT THEM DOWN IF YOU DO YOUR PART. I JUST BOUGTH A MODEL 37 20, SO I BELIEVE. AS FAR AS BUCK SHOT I WOULD SAY NO,I HAVE SEEN IT USED AND IT WILL KILL DEER BUT NOT AT 50 YDS, ALSO YOU DONT GET A BLOOD TRAIL TO FOLLOW.
GOOD LUCK AND KAPPY HUNTING