6creed with the powders I have run, pushes bullets 100-150fps faster than any 243 I have seen. For example, I don’t know if anyone pushing an 87vmax at 3600 in a 243. I do it in my 6 creed with staball 6.5This isn't true. 6 Creed will not match the case capacity a 243 has. That means that you will be able to run some of the slower powders in a 243 that you cannot in a 6 creed for the same velocity. In a creed you will end up topping out on velocity due to running out of case capacity. Actually a 243 will do everything at 6 Creed will do and more. The only thing the creed has going for it over the 243 is a longer neck. If that's what you want, check out the 6 SLR which beats both of those two. And it is one of the most simple cartridges to form. It happens on the first pass in a sizing die. Get you all the case capacity of a 243 with a 300 thou neck.
Agree that a 243 AI is a pretty decent answer as well. However, I do not think fireforming for it is a pain in the ass. It's actually really easy. Just run a couple rounds down the barrel to smooth out the throat and get a half-ass decent 243 varmint load going and then finish up your batch of brass with that load and then voila. It's all fireformed.
I would agree a 22 Creedmoor is a good answer, but I definitely think a person needs to consider their barrel twist carefully and take advantage if they are at a higher altitude of using a slower twist.
I can run 70 BTIPS in my 6 creed at 3780 with varget. Haven’t seen anyone run them that hard in a 243.
I agree that when you load the same powder charge in a creed and 243, the 243 will get a couple FPS faster but you can run a 6 creed harder without crazy pressure signs. Not that the 243 is a slouch. In all reality it doesent matter. Both will reach their destination with energy to spare for coyotes but I’ll put my creed up against any 243 in a speed contest.