Nothing wrong with a Howa Mini, I have one myself, although it's a 6.5 Grendel. Nothing wrong with a 223, I have a bunch of them, and it's one of my favorite calibers to hunt with. But, you already have what is coyote killing machine in the 243. Load it with some bullets weighing between 55 and 85 grains, and it'll do the job.
The problem is that the .243 is an older BDL model with gloss blueing & a gloss walnut stock.
