Sniper: Chainkiller / Perfect Headhunter boni reset when hitting enemies with armor plates.

[JC667]

After stacking up my Chainkiller bonus "Perfect Headhunter" to max, I basically one-shot everything.

Well, except for plated enemies (like Heavies, having multiple plates everywhere, or the Machine Gunners and Hyena rushers with their helmets).
Then, I blast off the armor plate with one shot, but my Perfect Headhunter stacks also reset, losing all damage of its damage bonus.

So do You guys know how to circumvent this?
Any weapon/gear talents that I can use that 'pierce' through the armor, carrying the rest of the damage into the target?
For example: The headshot damage is ramped up to 50mio, the Heavy Helmet eats 20mio. Usually the remaining 30mio just go up in smoke. Any way to confer those to the head?
Or talents that bypass the armor plate?
("Determined" talent transfers body shots to the head, also popping armor plates first, so I think that won't help me much)

At the moment I'm running Chainkiller with 4pc Hotshot set and Airaldi Concussion backpack to keep the other damage multipliers up. (So instead of 50mio (PH) or 2mio (no boni) my next headshot (after the armor plate breaker) does around 10mio damage.)
The "Determined" weapon talent is quite fun too, especially against those annoying armored robots.

[Annihilator]

I think is normal