Update 27.2 (2020-03-05)
It is worth noting we are fixing a UI inconsistency that is ‘Display Only’. Right now the Arsenal shows Status Chance affected by Multishot, which makes reading the new >100% value confusing. For example, the Arsenal might say 120% but really the Status Chance is 80%. We don’t have Multishot affect any Critical Stats (Chance or Multiplier), so we are fixing this display inconsistency. Multishot now has its own Stat.
Shotguns have a unique Role here based on a very patch-work history with how they interact with Status Chance. A Shotgun that shoots 99% Status Chance would give you 35% (roughly) status per pellet. 100% Status Gives you 100% Status per pellet. This huge jump in performance happens with just a 1% gain - why? Well, to answer that we have to look at our choice to make what the UI conveys reality. It would feel broken to shoot a Shotgun with 100% Status and not see a perfect spread of Effects. In reality, to make Status consistent we have to treat Shotguns as a special case.
Shotguns as a special case means we have buffed the Status Chance of all Shotguns by x3 or greater. The UI now behaves to show the reality that you are determining Status Chance per pellet.
Update 17.0 (2015-07-31)
Several changes have been made to shotgun weapons across the board -- resulting in a list of changes similar from weapon to weapon. The following list of changes apply to all Primary Shotguns with exception to the Phage:
Increased damage across all shotguns.
Damage after projectile falloff has been increased for all shotguns.
Some shotguns have been given improvements to reload speed.
Some shotguns have received improvements to their projectile speed.
Death at close to mid range will now toss enemies into a forceful ragdoll.