1] There's no fighting them unless there's a semi-organized effort (ie neighbors and others participating). You wouldn't want a confrontation infront a home or when they are expecting it. You'd want to organize, then ambush them on their confiscation route. Get them in the open with a massive hail of gunfire. Then run or evade. The longer range, the better. Think Lexington/Concord - but more guerilla style than even those battles.
2] You don't have a choice as to whether or not you'd "give" them a particular gun.
WAKE UP.
You aren't giving squat - THEY'RE TAKING.
You will be handcuffed infront of your home like a criminal while they ransack your home to find any arms that they can. The premise of the thread starter's post is that there's a cooperative nature to this. There is not. This is a forced confiscation. They are the master, you are the bitch. End of story.
3] If you thought about fighting back without an organized plan, you'd lose, because the 2-3 cops who banged the doors down had an entire platoon of National Guardsmen with fully automatic weapons fresh from Iraq. If you shoot the cops, they NG on your street will shoot back and take you out with their freshly acquired urban combat skills. They will saturate you and your home with firepower. If you've seen raw footage of what our guys do in Iraq, trust me, you don't want to go up against that. At least the Iraqi's have full-autos, RPGs and 2ft thick solid concrete wall contruction virtually everywhere for cover. You have semi-autos, no explosives or rockets, and wooden or cinderblock homes, and worst of all - no experience. Good luck.
Amazing, the cops are the badguys, but the brainwashed nationalists condemn any negative statement about the NG, despite their participation to guarantee the of authority of the police via physical presence of force which makes them 100% complicit in the crimes. As if anyone is impuning their Iraq service. It is the participation of *some* NG in the confiscations that makes them the enemies of freedom. Sorry, had to throw that in.
Since all of these options look bleak. The best idea is to not keep all your eggs in one basket. Way before any disaster, one should hide rifles and ammo in different locations that will not be easily found by confiscators. Let them take what they can find, then later on it is your choice what to do - at least you'll be armed. You can dig up your arms, and use them for defense against looters and to stay low, of if a "movement" rises up, join them and get a little justice later on.