Since I don't reload I'm limited to factory ammo,I've had 100% success using these as regulars,to 300 yards Hornady 24 grain NTX Superformance at 4400 fps,never lost nor missed one at those ranges. Stretching 400 to 500 yards rare but does happen,i'll go with Hornady 40 grain V-max superformance at 3900 fps, but the real sleeper and a deadly round is HSM Trophy Gold 35 grain Berger match varmint flat base at 3900 fps and a BC of 0.262 will buck wind and although i've only stretched it to just 500 yards,i'm confident it can get the job done at 6hundred. My cheap rifle is a Thompson Center Venture ,1/10 twist a rare bird in 204, 20X variable Weaver Grand Slam,my trigger was done by Mcarbo in Florida and breaks fantastic at exactly 1 lb.The Thompson will shoot with the best of anything and not embarrass me.Love my 204 .