Stormbolter with scope

[T10]

One of the Marines has a scope-thing on his storm bolter which appears to have some significance, but I can't see any special rules for this...

Is it simply cosmetic?

-T10

[wilsongrahams]

Yeah, though it is also listed and pictured seperately it is purely cosmetic in game terms.

You could always introduce special rules should you wish though - eg, reroll one shooting dice per shot, or gains sus fire bonus even when moving etc.