I would say your experience is typical of most some fall quick and other muster a scamper but 50 yards for a deer is a pretty small distance to cover any way you look at it.

As to the difference's in my case I used the BST for several years in my .270 performance was identical to what I have experienced with the NBT. I switched to the NBT b/c my other rifle preferred them in terms of accuracy. Since then I have never bought BST as the NBT's have proven to be both accurate and reliable for my deer hunting needs.