High power mags are a little weak in my opinion.
Currently, they don't actually increase damage as intuition would suggest from their labeling. They just prevent damage falloff at the distance of 75-100m.
This isn't bad per se, in fact it's quite useful on marksman rifles since that's an ideal engagement range for those weapons and retaining consistent damage at that range is important for DMR's.
My problem with that though, is that high-power magazines are present on many classes of weapons, yet statistically appear tailored specifically for marksman rifles.
Now that the issue is (hopefully) brought to Dice's attention, I would also like to suggest my own solution just in good spirit.
High power magazine: Damage falloff prevention range increased from 75m-100m to 75m-150m.
I don't want to give it bonus damage, since I feel like the TTK is relatively okay across the board in this game and I don't want to alter it (some outliers of course are in need of adjustment, such as the K30.)
Therefore I feel like my change will help weapons such as Assault Rifles help fulfill their role of mid-range assault much more effectively. I would like to see this change because weapons such as the AK and Scar really just feel like glorified SMG's because of the pitiful range. It is true that they are usable at range at the very least, but they really are below par. Especially the Scar, I feel like it should be the premier "ranged assault rifle."
My proposed solution presents us with another problem, however. What about High-Power magazines on SMG's? It's not like you can use them on anyone past 50 meters anyway, so what on earth is the point of preventing damage falloff beyond 75m?
For that question, I propose an addition to my earlier change.
High power magazine, my attempt to balance it across all weapons: Prevents damage falloff 75m-150m, penetrates thin materials, and causes heavy flinching and staggering on struck enemies. Struck enemies will also automatically be kicked out of ADS (aim-down-sight.)
This change would very slightly step on the toes of Armor-Piercing mags, however I do not believe it is a significant overstepping of boundaries.