I shoot the 39 gr. Blitzkings out of mine. My longest shot on a PD was 614 yards, and that seemed like the limit for me with the optics and wind I had. I generally keep the shots to within 500 yards for PDs with most in the 300-400 yard range.
I've got a bone stock Savage Model 12 in .204. I've got the thumbhole stock, with fluted bull barrel. My gun loves 39 gr Blitzkings, but hates 40 gr vmax. A lot of people can't get the 40 gr to group but 39's work great. I get about 1/2 MOA out to 300 yards if I hold my own. I've taken p dogs out to 500 with it, if conditions are right I'm sure 650 is very possible as long as you have the glass.
Bought this SS flutted factory varmint barrel from Northlander years ago and put it on an old 223 Tacticle that thought it was a shotgun.
This barrel never liked the 32 grainers in any mfg but does alright with the 40 grain Vamxes(½ to 3/4 MOA consistantly) with Tac powder. What it really does well with is 39 grain Sierras and a full load of Benchmark! If we are having a good day its a bad day for prairie dogs out to 500 yards or so, inside of 350 they dont stand much of a chance....depending on my ability to read the wind. It might do better with a better scope but the 12x Leupold works for what I've asked of it. This gun also has a 223ai barrel that will outrange the 204 with heavier bullets but has not been on the gun since I bought the 204.....Not really sure why?
As good as it is it will still will not hold a candle to the 20PPC shooting the same bullet and powder. This is without a doubt the best $550 I've ever spent on a used rifle as it just plain shoots!! It takes the fun out of shooting inside of 400 yards.....Well? almost and has taken a couple @ 750 yards.