Look, everyone agrees that the HPAR does way, way too much damage for an infantry rifle normally carried by a Tier 5 or Tier 6 Power Armor. So in the interests of fairness and my policy of not accepting grandfathering as an excuse for poorly designed or rules incongruent setting elements that are still in use, I'm proposing a fix for it.
Instead of the HPAR's damage being Tier 7 or Tier 8, we reduce it to a set tier: Tier 5, Medium Anti-Armor. This retains its role as a primary firearm for Nepleslian Marines while not making it scads more powerful than comparable aetheric, antimatter, or plasma weaponry.