Time to Open a Can of Worms - Weapon Data in OOB's

[Suhiir]

LOTS of them.
And yes the changes from altering the accuracy are quite small. They're intended to be.
The ones from changing the range on a rifle can be quite significant at times. Because now that can shoot just a bit sooner then most opponents thus supress or damage units before they get into range to fire back with their primary weapon (most of which have range 8, 400m).
In most cases this has the effect of lowering the damage your units take thus allowing them to be a bit more durable.
This could also represent to the generally better training and morale Marines have, the body armor, whatever.
All-in-all it does give them an "edge" without being overpowering - at least from my tests.