Kcnboise: Again the correct answer to your "popping" inquiry now that you have decided you are shooting/Hunting Prairie Dogs with your 223 - IS - the Sierra 50 grain Blitz (NOT the BlitzKings) bullets.
Again this bullet WILL really "pop" Ground Squirrels and Rock Chucks along with Prairie Dogs!
I have used these bullets for a VERY long time and have been very satisfied with them.
They ARE accurate and relatively inexpensive.
And to re-visit the the Ground Squirrels being "callt" Whistle Pigs - I spent 3 days this past long weekend at the Spokane, Washington Gunshow and MANY of the participants there were from Idaho and in fact several from Boise!
Our tables were unmistakeably leaning content wise toward long range shooters and Varmint Hunters.
We atrracted a LOT of Varminters.
I posed the question to virtually everyone who came along talking Varmints as to what "Whistle Pigs" are.
Everyone answered Rock Chucks!
Now again you can call your Ground Squirrels ANYTHING YOU want but in 51+ years of Hunting Varmints of all kinds all over the west I have never heard Ground Squirrels called "Whistle Pigs"!
Pertinent case in point: I Hunted one family ranch not far from Boise, Idaho for several decades starting back in the 1960's. The grandfather who was in his 80's back then and semi-retired but still living on the ranch, took me out one day and explained to me how his parents had homesteaded that ranch and they had tasked him with shooting the "Whistle Pigs" (Rock Chucks) when he was a youngster!
He and his progeny were still shooting the "Whistle Pigs" (Rock Chucks) after all these years and he wondered why the "Whistle Pigs" (Rock Chucks) were never shot out?
He also mentioned that during lean times of the Depression they would cook and eat the "Whistle Pigs" (Rock Chucks)!
He further relayed how the 3 to 4 pound "Whistle Pigs" (Rock Chucks) were the best eaters and that the big 10 pounders were to "fatty" to make good eating.
This life-long resident of the country east of Boise WAS NOT talking about Ground Squirrels when he mentioned Whistle Pigs.
As all during the time of our visit/Hunt we were SHOOTING Rock Chucks and he referred to them as "Whistle Pigs".
Speaking of the "noises" that Ground Squirrels make versus the noise that gave Wood Chucks and Rock Chucks THEIR nickname "Whistle Pigs", the Ground Squirrels noise is much less whistle like than the Rock Chucks noise.
The Rock Chucks do make a very shrill and distinct whistle like noise - Ground Squirrels make a much quieter and a more "peeping" like noise!
Thus the nickname of "Peeps" that is often used for Ground Squirrels around Idaho, Oregon, Montana, Nevada and Utah Varmint Hunting Campfires.
Another reason Rock Chucks are referred to as "Whistle Pigs" is because they often (once mature) become VERY obese and covered with fat - like a pig.
Rock Chucks whistle, and they often are very fat, thus the nickname "Whistle Pigs".
Another pertinent point is many friends of mine (who Hunt and live where there are Wood Chucks) from back "east", where Ground Squirrels DO NOT live, refer to Wood Chucks and Rock Chucks as "Whistle Pigs".
Good luck to you on "popping" the Colony Varmints of all names and varieties this season!
Hold into the wind
VarmintGuy