I used to shoot svc rifle competitions; was never great but was more about having fun and improving as a marksman than winning anything. I grew up shooting off hand with a pellet gun, then .22, and moved up from there. I know my abilities and would consider myself an "above average" shooter. That being said, you have three things going against you when it comes to trying to get the "one hole group": Shooter inconsistency, rifle inconsistency, and ammo inconsistency. No matter how tight your tolerances are, there is going to be SOME variation between one loaded piece of ammo and the next; some variation between one shot fired and the next in regards to barrel resonance; and no matter how still you may be, or how perfectly you apply marksmanship skills there will be some variance in you between shots. Everyone who is interested in precision shooting does what they can and what they feel reasonable to eliminate as many of these variances as we can; from weighing brass and bullets to using precision machined parts in the rifles we shoot to practicing how we shoot... its part of a total system. Sometimes those variances and the sun and moon and jupiter align and you get that nice one ragged hole group. Other times the pendulum swings the other way and you end up with a much larger group than the norm... the better you, your reloading practices, and your equipment are the less the pendulum swings.