We are not talking implicitly about Trajectory, its the fact that the fundamental laws of thermodynamics is being challenged here.
Ballistics is a field like any known science in mathematics that describes our world, based on empiric evidence and recorded data.
The OP is niggling over the difference between 200 fps and 207 fps which if you use the Joules calculator, shows that its nearly there at max power. As for the range, that is where you resort to ballistics calculators that can work that out based on what you put in, things like elevation, direction of shooting if a really tech site as earth spin still on Airsoft levels affect the BB, you see it in action, its called gravity.
There are some fundamentals in our world that you can not get around or break the rules of, it is impossible, like the race to max out the joules... the BB only carries the energy that was imparted on it (simple world view for this demo) and can not gain any energy but lose it over time and that equates to distance.
Seriously, give the Ballistics calcs a go and it may help land you in the ball park area you are aiming for or at the least, tell you if you are under or over powered. Incidentally, the calcs you use for this in every airsoft game, are used in real steel.
So they scale with the size and powers involve, thermodynamics baby...
When I did it in physics at uni in my foundation year, its a heavy subject and one that can make your head go pop if you're not paying attention. The take away I got from it was simply that rule, you can not extract more energy from something that has energy to give up. So you can't make a 0.4g BB go faster on a set joules output, you will see a big difference with different BB weights as its like airgun shooting or live rounds, same rules, divergent weight projectiles and again, ballistics rules the day.
So any talk on accuracy deviations from hop ups, really are not an issue here, its all about the joules, BB weights and how you shoot, you can then consider other factors when you determine that you are shoot correctly.
You wouldn't believe the numbers of players that hold pistols gangsta thuglife style, apply pitch to rifles and so on, all these moves affect things like accuracy and range. Unless you know how to hold a rifle, cheek it properly and get to know your RIF without sights, I play without using sites and I can hit spinner targets and people with accuracy, if you haven't seen my airgun target shooting... gives you an idea on how you can be accurate and hone your skill to use in game play.
Suggestion to Mr Dad is to study up on ballistics theory and watch a few real steel shooters, there is a lady shooter, Kirsten Weiss, look her up, an excellent shot and skilled lady. She talks about proper gun use, it may help you iron out any possible wrinkles you are inadvertently introducing. I have been there myself, so it pays to listen to some other advice on improving shooting skills, I only became aware of something I was doing that shouldn't have been doing as it did affect my shooting and that is too many people do put too much pitch in their hold on a rifle.
In airsoft, I see plenty of people set up and "Chinning" their stocks, why? That really affect accuracy... cheek it properly and your accuracy goes up exponentially.
Not trying to preach here but rather help in drawing attention to things that many players dismiss, don't know if its myth or folk law but I hear stuff that makes me chuckle. As for the hop ups and RIF's in general, I am on the back foot here in terms of hop ups and things like that, what I am not on the back foot with is ballistics and shooting in general.
Here she is: https://www.youtube.com/watch?v=1YnQVS_HdrI
