Fellblade accelerator cannon

"Attacks made with the Blast (X) Special Rule use a Blast Marker to determine how many Hits are caused."
When making attacks with a Weapon that has the Blast (X) Special Rule, before any Hit Tests are made, a Blast Marker must first be placed to determine how many Hits may be inflicted by the attack. The Player making the attack must place the Blast Marker indicated in brackets as part of the Special Rule so that the hole in the middle is entirely over the base of any one model in the Target Unit. Once the blast Marker has been placed, the Player making the attack must make a Hit Test for the attack, and each Model from the Target Unit that is fully or partially under the Blast Marker will suffer 1 Hit if the Hit Test is successful.

*Hits on Other Units*
If any Models form Units other than the Target Unit are fully or partially covered by the Blast Marker, then a new Fire Group must be created for those Hits and set to one side. Continue resolving the Shooting Attack on the original Target Unit, and once that Shooting Attack has been completely resolved begin a new Shooting Attack to resolve those additional Fire Groups generated for Units other than the original Target Unit.

If the Hit Test is unsuccessful then no Hits are inflicted and the Player making the attack must make a Scatter Roll for the Blast Marker (see the Rules for Scatter in the Warhammer: The Horus Heresy - Age of Darkness Rulebook). Once a Scatter Roll has been made for the Blast Marker and it has been moved, one Hit is inflicted on a Unit for each Model from that Unit that is wholly or partially covered by the Blast Marker.

"Weapons with the Ordnance (X) Special Rule double the value of a Characteristic when Stationary"
When making a Shooting Attack with a Weapon that has the Ordnance (X) Special Rule, a modifier of x2 is applied to a Characteristic if the Model with that Weapon is part of a Unit that remained stationary in the Controlling Player's previous Movement Phase (if that Characteristic is AP, then the AP is instead changed to AP 2). The value of X in the specific variant of the Ordnance (X) Special Rule determines which Characteristics gains the x2 Modifier.

"Attacks made with the Blast (X) Special Rule use a Blast Marker to determine how many Hits are caused."
When making attacks with a Weapon that has the Blast (X) Special Rule, before any Hit Tests are made, a Blast Marker must first be placed to determine how many Hits may be inflicted by the attack. The Player making the attack must place the Blast Marker indicated in brackets as part of the Special Rule so that the hole in the middle is entirely over the base of any one model in the Target Unit. Once the blast Marker has been placed, the Player making the attack must make a Hit Test for the attack, and each Model from the Target Unit that is fully or partially under the Blast Marker will suffer 1 Hit if the Hit Test is successful.

*Hits on Other Units*
If any Models form Units other than the Target Unit are fully or partially covered by the Blast Marker, then a new Fire Group must be created for those Hits and set to one side. Continue resolving the Shooting Attack on the original Target Unit, and once that Shooting Attack has been completely resolved begin a new Shooting Attack to resolve those additional Fire Groups generated for Units other than the original Target Unit.

If the Hit Test is unsuccessful then no Hits are inflicted and the Player making the attack must make a Scatter Roll for the Blast Marker (see the Rules for Scatter in the Warhammer: The Horus Heresy - Age of Darkness Rulebook). Once a Scatter Roll has been made for the Blast Marker and it has been moved, one Hit is inflicted on a Unit for each Model from that Unit that is wholly or partially covered by the Blast Marker.

"Weapons and other attacks that have the Stun (X) Special Rule have a chance of inflicting the Stunned Status on the Target Unit."
If a Shooting Attack made for a Weapon or Model with this Special Rule inflicts one or more Hits on a Target Unit, that Target Unit must make a Cool Check in the Morale Sub-Phase of the same Player Turn. If this Check is failed then all Models in the Unit gain the Stunned Status and if the Check is passed then there is no further effect. The value of X attached to this Rule is applied as a negative modifier to the Cool Characteristic of Models in the Target Unit when making Checks caused by an attack with this Special Rule, if the attack includes multiple Weapons with different versions of this Special Rule the modifiers do not stack - use only the greatest modifier.