This is a DIY (do-it-yourself) mini-mod.
The weapon ranges are governed by the
file. Or if your game is patched to version 1.1a then:
Open up baseitems.2da in the editor of your choice (this is pretty big table, so I recommend Excel). I take the two swords (silver and steel) here as examples — you will need to make the same changes to all the other lines you want changed — in the column named "MaxAttackDist". Anyway, here is how it looks now:
1 steelsword 0.8 2 silversword 0.8
And this is how the lines above look after the update (again, I show only the "MaxAttackDist" column here):
1 steelsword 1.2 2 silversword 1.2
Save the file with the same name and put it in the \DATA\OVERRIDE directory.
There is no need to start a new game; just load a saved game and enjoy your mini-mod.
See how it feels and experiment with new values as you like. Other mods may modify the same file (like the Item stacking mod), so watch out.