Glassed him from a mile away. First time we had seen him and had been glassing that area for a week. I was with my brother and as soon as he stepped out of the timber we knew he was big and we took off after him. Wind was perfect. Right from him to us. Got to 300 yards and my brother held back while I crawled another 50 yards. Laid down and got the bipod set up. He was laying down and I was going to get my coyote call out and give it a blast to get him to stand up. Out of the corner of my eye I catch movement to my left and see the little black bear we have been watching for a week in that area about 500 yards out walking across the meadow right towards the big black. I leave the call in my pocket and figure when the big guy sees the little guy he will get up to put the run on him. The little black gets within about a 75 yards of the big boy when the big boy saw him and stood up broadside. One shot from the 300 mag. Heard a big whop and he took off into the timber. My brother came up to me and asked if I hit him. I said, "didn't you hear the whop"? He said that he had the binocs focused on him and he didn't even flinch. We walked the 250 yards down to the impact point and couldn't find any hair or blood. Right where he stepped out of the timber there was a huge pile of droppings. I circled about 75 yards and came in behind where the impact area was. I worked my way back down the trail and there he was piled up about 60 yards from where he was hit. Gutted him out before it got dark and headed back to the truck. Came back with help the next day to get him out.