man and machine
you need a decent machine, but most importantly a decent man behind it. just practice until it becomes natural.
after all give me an F1 car, ill crash it at the first corner. but thats me being confident, i wont make first corner.
shoot your rifle first, when you can do it well enough, try some mods, one at a time, spend some time evaluating, what difference it makes, good,bad,ugly. if good shoot it some more, make another mod and repeat. if it goes the wrong way undo that mod. by all means try your mod but only after knowing what your rifle is capable of first. if not how will you know if it has improved?