If you hit the head a shotgun is effective! “your” helmet will not protect you! But then again i have my steyr aug at home. A .223 full metal jacket will penetrate every police armor.
Not that it would help me this much (because i still would get killed if swat storms my house) but at least i would die knowing that i took one of this “nazis” with me.
The heavier armor available is why I have several hundred rounds of 7.62x51 API. If the tungsten core doesn't get you, the 3,000 degree incendiary will. And if I live long enough, no body armor in existence stops a .338 at close range. Head shots are the best option, but I doubt you will have time to aim that well. Dark, the invaders have probably thrown their 'diversion' devices (nice euphemism for flash grenade), and you are the one caught off-guard, not them. The only thing that will save you is something that throws them off their well rehearsed invasion rhythm.
Introduce confusion and panic. That is what they are counting on you being consumed with. Return the favor, and you have a chance, however small, of winning the engagement.