Unfortunately this isn’t really an issue with the Bolter and Power Sword, they’re both surprisingly healthy weapons. The Bolter is inaccessible and very tight on ammo, the Power Sword relies on its killing power (which is far more restrained in Heresy+) to compensate and has one of its weapon statistic slots wasted with Cleaving being split in two.
You can see why the above drawbacks make the weapon a real prize for the Veteran, who is designed specifically to mitigate most of them?
What’s really killing weapon balance is the enormous gulf between these powerful-feeling weapons that synergize well with their classes and everything else.
A Revolver might be able to match a Bolter shot-for-shot in many fields but it has a third of the ammo pool and a slower reload. And you can repeat this over and over for almost every other weapon in the game.
“This weapon would be good, but…”
Autogun? Lasgun? Staves? Sidearms? Heavy Stubber? Pointlessly hamstrung on effective damage, armor penetration, ammo pool, and usability compared to higher level peers. Why does a laspistol have less than 25% of the equivalent ammo to its higher tiered counterpart? The higher tier counterpart doesn’t need to be nerfed, the laspistol needs to have a functional amount of ammo so that they can begin to compete on the same playing field.
Catachan Fang? Force Sword? Axes? Dueling Swords? Heavy Swords? Shovel? Same thing, just randomly worse across the board in terms of damage, armor matchups, moveset, or require weapon blessing synergies to function. The problem isn’t that my Eviscerator can go through half a pack of armor with a well-placed swing, it’s that my other weapons never improve or develop; they just remain outdated fodder for lower difficulties that have to blow half their power budgets on cleave traits and armor shred just to struggle to a form of basic functionality.