Me thinks me smell something.....Come on....2100 yards rockchucks.....give me a break......LOL

Looks like a killer tomato from that old b movie.

can't see why anyone would pick a 223 over a 22-250.

I'll answer that....
You're in Virginia.
You have groundhogs, but not enough to melt your barrel, especially on Sundays (that's a dirty shame, by the way).
A 22-250 is actually probably better than a 223 given the size of the target and the rate of fire -- in Virginia.
But if you come out West to South Dakota and have a good guide and good shooting, or luck into a good ranch on a typical summer day, your 22-250 will start to droop.
I've had hunts where my 22-250 buddies had to sit and wait while I whaled away with the 223 -- especially when I used special Blue Dot loads that move a little bullet fast.
All that said, the ultimate varminter is the one that YOU like the best. I'm lucky in that I have several. Each is the "best" for the application at hand.
So the 22-250 is the perfect "core" gun for you, for others it's the .223, for others a six, or .204 --

I you like seeing your hits -

I'd pick my Tikka 204 varmint rifle.

I'm new at Coyote hunting but this is what I use.

Rock River Predator Pursuit 20" barrel. Leupold Vari-X III 1.75x6x32

I use a 30/06 on coyotes, but sometimes have to pass up shots that don't have a good backstop. My ideal choice would be a 6BR, 243AI or 243. with a match barrel for LR shooting.

To be the smart a$$ here I'm gonna say............. What ever gun I have with me at the time. I'm mostly a predator hunter (and yes, predators are predators and not varmints) but it seems to me that varmint hunting runs a rather large gambit. For an eastern ground hog guy a lightweight sporter in .22hornet may be perfect, a rock chuck guy out west may prefer a .22-250 or .243 and prairie dogin may be best with a .204 or .223 heavy barrel.

Personally I think a .22-250 with a 20" varmint contour barrel would make a great compromise gun. Light enough to pack, but a little heavier barrel to not heat up as fast.

CB

First you have to decide what all you're covering with the varmint label. Little rodents? Furbearers like raccoons and coyotes? Cougar? Bear? What happens if you go outside the US? I'm told of people shooting baboons and kangaroos as varmints.

Then you have to ask how far away, how many shots in a sitting, and whether you're trying to save hides etc.

"Ultimate" isn't so easy to pick without some context for the choice.

With the right equipment it can and has been done, find it interesting that you joined the fire just to call me out.
If you are smelling something you most likely shat yourself when you realized you are wrong.