when new host found after migration almost every time weapon got crashed(bullets go to negative),at least for scar...that should be fixed!

I haven't seen this. In fact host migration has been really successful lately for me. I've never lost ammo because of one. I did have a host migration when I was respawining and when it all came back, I was firing my gun uncontrolably and way past the ammo limit. I still hear other players doing this on occasion. Weird.