I have been reloading my predator loads for a long time now and it is really fun to experiment with different loads and shot sizes. I shoot a mossberg 835 have tried everything imaginable in it as far as shell length, shot and buck shot sizes, powders, primers,wads, hulls, you get the drift. I have spent a small fortune over the years at Ballistic Products trying to find the perfect loads for both coyote and fox. It used to be fairly reasonable to reload but components now are ridiculously high and setting up to do what I have done would now be crazy money. I have also tried all and I mean all the available factory offerings in all configurations. After a few years of experimenting I have come to the following conclusions: First of all, and probably the most important is that it is difficult and in many cases fruitless to try and replicate or improve upon the available factory offerings. An exception to this is the "Dead Coyote" loads you mentioned. I have found them to be adequate but not enough to be worth 3 or 4 bucks a shell it is not hard to "outdo" these loads in my opinion. Secondly, after all my "fun" reloading I have found myself using factoy loads at least 90% of the time now. The loads I highly recommend as they work great in my gun are the following:
1. For coyote..........winchester 3.5 inch magnum buckshot loads in #4 buck and #00 buck. The 4 buck loads carry 54 pellets and pattern way better in my gun than Dead Coyote ever thought of and at $10 a box of five are reasonable. Next is the same shell..Winchester 3.5 inch with 18 pellets of #00 buck. Also a great heavy load for coyote. Both these loads are great long range loads and are all I would need in any situation for coyotes. Dogs that get within shotgun range don't get away! By range I mean 60 yards or closer.
2. Another factory load that is great for fox and also coyote at a little closer distance is the Federal Premium 3 inch loads with 2oz copperplated # BB's. These loads hit hard and will roll em up in short order!
Don't get me wrong, I am able to handload some excellent rounds for my gun and I'm sure anyone who went to the same effort I did would undoubtedly find some sweet loads for their particular shotgun, but my guess is that there is an equally effective factory load out there that would save you alot of time and money. FWIW