RE: what should i use in my 12 gauge for coyotes?
Well execept for my posting about my bobcat that got away after I used #4 buck on him (which I believe now that I just completely missed the cat), I'd go with 3" magnum loads of #4 Buck shot. It has 41 .24 caliber pellets and it hits hard and keeps a tight pattern.
Remember, there is a difference between #4 shot (birdshot) and #4 BUCK SHOT. Read the box carefully. I'd never use 3" 00 buck wether it's the 12 or 15 pellet configuration. Past 15-20 yards your pattern might very well be too spread apart. If you insist on using a bigger pellet than #4 buck, try maybe a 3" load of #1 BUCK shot. That has 24 pellets of .28 caliber (as I recall???) or .29 caliber (can't remember off had the pellet size).
Also another option is to use a 3" magnum, 2 ounce load of BB shot, made by Winchester, Federal and Remington. You may have to order that load from you local gun store. It's a lot of shot, just slightly smaller than #4 buck, yet much more pellets. And it hits like a Mac-Truck on coyotes.
Good luck.