I agree that Aiki's method is precise, but time-consuming. It also loses some traction at the lower ROF values - what if you have a weapon with an ROF of 2 - you need to roll '00' to hit with both rounds? Maybe we need to be rounding up, so that values from 01 to whatever qualify to hit with one round without resorting to "no fewer than one" rulings?
Doing so gives us these sorts of scenarios:
I'm a strong marksman (100% with pistols) and my ROF is 2. I have a 50% chance of hitting you with both rounds (roll 51-00)
I'm an above average marksman (60% with pistols) and my ROF is 2. I have a 1 in 10 change of hitting you with both (roll 51-60) - one sixth of the time when I do manage to hit.
I'm a novice marksman (30% with pistols) and my ROF is 2. I have literally no chance to hit you with that second round - I'm a poor enough shot that I need an ROF of 4 to have a shot at hitting with a second bullet, and even that only happens on 26-30
Realistic? Anyone?
If so, we can solve the complexity issue with cheat sheets. Figure out the likely numbers of rounds that will be fired from the weapons in your game and create a cross-reference for the impacted player. Guy with an AF7 weapon would need to know where his breakpoints were (15 to hit with 2, 29 to hit with 3, 43 to hit with 4, 58 for 5, 72 for 6 and 86 to hit with all 7)