I Have a Mossberg 500 20 Gauge A Friend wants to use turkey season....
I used a full choke in it, But I read that Winhester Chokes Fit in my Moss, Is it true? And Safe?

Yes they have the same threads and work. My Mossberg turkey choke didn't shoot worth a darn in my Mossberg, shoots great in my Dad's Winchester though [&:]

Browning Invector will also work in your 500. Winchester, Mossberg, and standard Invector (not Inv.+)all have the exact same threads.