So yesterday, my dad and I were driving a small swamp when he kicked up a nice doe.  It ran towards me, and then at about 75 yards, it turned and ran to my right.  I waited until everything was clear before I started shooting.  I emptied my .280 Ruger MKII stoked with 140gr Sierra Gamekings over 57grains of RL19 (5 rounds).  On the last shot, she dropped.  I could tell that the 1st and 3rd shot hit her from the way she lost her stride, but it seemed #2 and 4 missed their mark.  
So today we skinned her out and I was amazed at what I found.  All 5 bullets hit their mark!  The 1st 4 shots were right behind the shoulder, and the last when entered behind her ribs at a severe quartering shot.  This bullet made it into the boiler room and did it's job.  The 1st 4 rounds literally exploded under the hide.  They didn't even pierce their way into the chest cavity.  I think the reason the last shot made it in was because she had made it out about a hundred yards or so and the velocity dropped off.
I should have known better but I found an un-opened box and I thought I would give them one more try.  Over the last 15 years or so, I have only had one pass through with these bullets, and that was a mule deer at about 150 yards.  Otherwise, anything up close, the bullets explode, but usually in the chest cavity where they cause a huge amount of damage.  
I'm looking for a different bullet to try and I need some recommendations.  Would a 150 or 160 grain Gameking hold up?  The accubonds shoot well, but they don't really seem to open up much.  I thought about Barnes or the new Hornady GMX.  I have also heard a lot of good about the Scirroco.  
We only have tomorrow left for the Wisconsin Gun Deer season, so the .280 with be a safe queen and my .308 will be used for the remainder.  I don't feel very comfortable using the .280 on deer.  I would have a hard time sleeping if I lost a deer.