Toying with -DR mods of ammo, armor resistances and other stuff is not the thing really needed. Look here carefully:
14:30:24 • Motoko was hit for 64 hit points by you.
14:30:29 • Motoko was hit for 33 hit points by you.
14:31:45 • Motoko was hit for 68 hit points by you.
14:32:04 • Motoko was hit for 65 hit points by you.
14:32:08 • Motoko was hit for 49 hit points by you.
14:32:38 • Motoko was hit for 59 hit points by you.
Out of 15 bursts in total, 6(!) of them were unreliable. Stopping Power won't fix anything with this, just increase alpha (maximum) strike to characters with DR above 65.
I found that annoying on XL rifle and P90 too, especially in hexing.
Conclusion at comments above:
Perks that counters other perks in this way is not good in my opinion, because they neglect the primal role of tank - to tank damage. Basically right now it's easier to tank normal damage than to deal normal damage, no doubt, but. Remember what avenger does with paper characters\jet users\snipers and always keep that in mind when thinking about this weapon.
What I suggest as perk for bursters:
Level 24+ one that will increase burst hitchances from 95% to 100%, so you'll not miss bullets with guarantee (unless target has high AC, here you should counter it with high weapon skill). Low requirements, so it'll be universally available to other guns also.