Since the release of Black Crusade, and now into Only War, the Standard Attack Action is a Half Action that adds +10 to WS or BS. Why? It's as if thousands of players were complaining of not being able to hit anything, due to poorly generated starting Characteristics, and so changing Standard Attack to include a +10 would make everyone feel like they were getting off with some sort of buff. But why give the Standard Attack Action any bonus, when you can just add 10 to the starting WS and BS? Let's say a character starts with a WS/BS or 32, takes a Half Action Aim and follows with a Standard Attack. The characters effective target is 52. Fine. Let's then say his/her WS/BS doesn't change, but the character has the Swift Attack Talent, which has a +/-0 modifier to hit, or the Lightning Attack Talent that has a -10 modifier to hit. Both of these Talents require a Half Action to use, but Swift Attack is a Talent that implies increased Skill, allowing additional hits and benefits from Aim Actions. Lightning Attack is a Talent implying even more skill than Swift Attack, yet its associated negative to-hit modifier is negated with a Half Action Aim? And the character then only gets an Aim bonus if he/she spends another Half Action, what…revving up like the Tasmanian Devil? Sure, more hits with Lightning Attack, and blah blah. But…
WS 32
+Half Action Aim (+10)
+Standard Attack (+10)
WS 52 (adjusted)
Then WS 32
+Half Action Aim (+10)
+Lightning Attack (-10)
WS 32 (adjusted)
Yay. I'm a massively talented melee machine, lashing at my opponent with a whirlwind of blows that have a reduced chance of hitting and achieving less DoS. It makes no sense. I'll keep the single attack at 52, thank you.
Or…
BS 32
+Half Action Aim (+10)
+Standard Attack (+10)
BS 52 (adjusted)
Then BS 32
+ Half Action Aim (+ 10)
+ Full Auto burst (-10)
BS 32 (adjusted)
Again, I'll take the single shot. Maybe even make it a Called Shot, since chances are equal to a Full Auto burst of actually hitting in the first place, with the added bonus of choosing the weak spot of my target and likely doing more damage than a few randomly spaced dinks.
So I say, if you want players to be able to hit something and feel like they're getting something out of it, just raise starting WS and BS characteristics by 10. Save the time and headache of adding yet another modifier.