If you’d like a new gun in a .223 go for it. A great lite gun and fun to shoot. Guy can never own enough guns.
Your .243 is a great option as well. I’ve used the .243 for this purpose for 40 plus years.
The shine.. back “in the day” all rifles had shine, coyotes didn’t mind. You can buy gun sleeves or no mar tapes to wrap your stock for stealth and protection. When hunting mine is laying besides me on stand, across my lap or up and outward depending on the situation. A blued barrel doesnt matter that I recall.
I have shot mostly 55 grain ballistic tips with great success and stretched them out a long way. As far as my abilities for sure.
Whatever you do, remember you are “calling” coyotes. Put more concern in your approach and method to getting them in close than how many miles out you can drop them and you will do well and enjoy a bunch.
Osky
An afterthought. In my case I’ve shot from Havre down to Eagle Pass on too many spreads to remember and I would say my average first shot is well within 100 yards. Other guys here may have other experiences, I’m not the end all do all. Hope this helps.
