Yes, lots of slugs...yes it is safe...slugs shoot better out of more open chokes, or at least that is the general wisdoom...the Trulock folks report better results with full or other constricted chokes, though...different brands and types of slugs will shoot differently in different guns, so experimentation is useful for best results.
Thanks! I recently fired some rifled slugs out of my gun and it worked really well, the devastation to my targets was amazing. Someone had an old car radio, so I decided to blow massive holes through it. The slug went through multiple layers of that thick metal and all the components and then went into the ground, unbelieveable power. 1500fps, 1 slug