Driftrider

With that 1-48" twist side-hammer you have, you made the right choice by going with a light-grained sabot. The PR 40s are a little longer than that twist desires. Those 48s, in many situations, shoot the shorter pistol sabot/bullets better... ie Hornady XTPs. If you ever get an extra $8 in your wallet, pick up a 20-pk of 180 or 200 grainers for that rifle & your wife.

Odds are, that thump you heard at 100 yards is the longer bullet tumbling in that slower twist rifle. You or the wife could turn that rifle into a 100 yard deer killer by going with shorter pistol bullet/sabots or the short light recoil 245 grain conicals called the Buffalo Ballets.

Just a suggestion!