Art, sorry; I was trying to be funny (unsuccessfully). He said that the prairie dogs *WANT* to get shot; I was wondering if the prairie dogs understood the question of "Do you want to get shot by my Remington 700?". Maybe they thought he said "Should I put a red *DOT* on my Remington 700?".
In all seriousness, Para, I don't think any kind of milsurp, even South African, will consistently make hits at that range (beyond 300) on a target that small. Under 150 it might with that good of a rifle, but 300 is a pretty long ways to hit a p-dog, despite internet commando assertions to the contrary, and I think you'll need good factory stuff or handloads to make hits past 250-300, even with a quality turnbolt like that. As for noise, I do not have enough experience to know whether .308 or something a tad smaller will make a difference in them bolting or not, but I kinda doubt it, esp. since something like a .243 for example, will be just as loud IINM, since you've got essentially the same amount of powder, but pushing it through a small hole (bbl diameter) I believe will make it louder if anything, not quieter.