RE: What gun would you use?
Your slugmaster will knock any deer down at 100yrds . I would use this.
The only thing I would take into consideration is if you know that your shots may be 125yrds and up I would then consider using the rifle.
Good luck and let us know what you decide and if you take anything!
KEEP HUNTING THE GREAT OUTDOORS & GOD ALIVE, PASS IT ON!