IMO, there are a myriad of factors that come into play that effect seeing the bullet impact. Recoil/cartridge, velocity, rifle weight/configuration, muzzle brake, distance to target, shooting position, scope power, sight picture/field of view, and overall shooting form. Given the precise spotting of hits is an important factor, I'll follow some basic practices:
-use the heaviest rifle I can that does not pose a problem for the particular use.
-use a good brake, and a cartridge/load that gets the job done with the least amount of recoil/muzzle flip. Overkill may have a penalty.
-use the lowest scope power/greatest field of view sufficient to hit, but also optimize the ability to acquire the target/game in the sight picture. "Always" keep both eyes open and follow through.
-if position is a choice, go prone. Regardless of position, make sure the shoulders are at a 90 degree angle to the barrel.-
-practice, and learn the positions and distances to understand where spotting hits can or cannot be achieved with a particular rifle
Just some thoughts.....