HVGC and Heat Signature stacking bug?

[acnoj]

High Velocity Gas Cylinder and Heat Signature stack in a multiplicative way:

35% armor penetration x 20% armor penetration = 48% armor penetration (NOT 55%)

 

The raw numbers form my test if you're interested are:

Rapid Shot Main Hand with no armor penetration - 58 to 61

Rapid Shot Main Hand with 5 stacks of Heat Signature - 63 to 65

Rapid Shot Main Hand with High Velocity Gas Cylinder - 67 to 69

Rapid Shot Main Hand with 5 stacks of Heat Signature and High Velocity Gas Cylinder - 70 to 73

 

Given an error margin of +/- 0.5 damage, those results are constant with multiplicative stacking and more importantly inconstant with additive stacking....Which is fine, that made sense to me until Gyronamics point out this:

http://www.swtor.com/community/showpost.php?p=4230212&postcount=17

 

In this test, you ignore 55% of the target's armor rating. 20% from Heat Sigs + 35% from your Cylinder.

 

Operations training dummies have 5814 armor rating (not visible to you), which translates through our armor formula to about 35% DR. With your setup, you cut that armor rating down by 55%, effectively turning it into 2616 armor rating. [5814 * 0.45 = 2616] 2616 armor rating translates through our armor formula to 19.5% DR.

 

So what's the story? Is this a bug?

[Sinsavz]

Dude...it's almost not even worth bothering to try and understand merc mechanics any more.

[acnoj]

Sure it is. The last two bugs I've found and posted are fixed in 1.3, so I will persist.

[Ifrit]

Sure it is. The last two bugs I've found and posted are fixed in 1.3, so I will persist.

 

thank you. keep it up.

[acnoj]

I just finished testing the armor penetration in 1.3:

 

Advanced Targeting ADDS to High Velocity Gas Cylinder, and together they MULTIPLY with Heat Signatures. All up the targets armor is reduced to 28%.