“...I DO have a .223 carbine, but a larger, lower velocity, relatively inexpensive slug makes more sense to me, here. ...”
“Your sense is wrong.”
I concur.
Here is a comparison video of .223 rounds. https://www.bing.com/videos/search?q=223+hunting+bullet&docid=607989660763623778&mid=8F1B8654124FC2EC4EFF8F1B8654124FC2EC4EFF&view=detail&FORM=VIRE
Unless you have a huge rodent or varmint problem, the cost of .223 hunting rounds should not be a problem. I dispatch 8-10 ground hogs every year with a 7mm mag; 50-200 yards. Perhaps a bit overkill but I don’t care.
Cost of PRACTICE would be the issue.
From that test the 40 grain Vmax would be the only round I’d consider, because I do NOT want the slug to exit. But, I’m not a reloader...