BWalker: I started Hunting Prairie Dogs back in the 1960's and have been a avid advocate of that endeavor ever since.
For the next 40+ years I suggested and helped set-up MANY neophyte Prairie Dog Hunters with their first "Prairie Dog rigs".
For that 40+ years I always suggested the new Hunter consider/buy a heavy barreled Rifle in 223 Remington - these guns are normally very accurate, somewhat mild of recoil, have long barrel life and have adequate ballistic performance to keep a new Prairie Dogger content.
Then in early 2,004 I bought my first Varmint Rifle in caliber 204 Ruger - I was amazed at this cartridges performance and its attributes!
Then in 2,005 I enthusiastically began advocating/suggesting that new Prairie Doggers use this cartridge (204 Ruger) - ALL I have suggested this to have been pleased with my recommendations to date.
I currently own and use 8 (eight) heavy barrel Varmint Rifles in caliber 204 Ruger, and the accuracy provided by each of them simply amazes me!
Indeed I proclaim the 204 Ruger to be more reliably accurate in factory Varmint Rifles than the 223 Remington!
I base this contention on the first hand experiences of not just myself but the observed results of MANY of my Varminting/shooting friends.
Couple this splendid accuracy with the flatter trajectory of the 204 Ruger (at distances which 99%+ of Prairie Dogs are shot - 500 yards and under!) the lessened recoil and the amazing lethality of those speeding 204 bullets and I have a new most favored, most recommended "Prairie Dog rig" - the 204 Ruger! (reference page 186 of the Remington 2,017 product catalog if you have ANY questions comparing the 204/223!).
Like sdgunslinger above I have a pair of exceptionally accurate Ruger Model 77 V/T's in caliber 204 Ruger - they are among my most accurate and favored of my many factory Colony Varmint Rifles.
Yep that would be my recommendation - look for a Ruger 77 V/T in caliber 204 Ruger strap on plenty of scope power and "go to town"!
Best of luck to you with whichever you choose.
Hold into the wind
VarmintGuy