For all those of you that do not use what I use... If it works for you, don't change. Never argue with success! That said, my rifle seems to like Federal Premium 168 HPBT. At 100 yards with a good rest you should be able to shoot almost 1 continuous hole. However, it is tough to do that with a 3-9 depending on the age and focus of your eyes. I have always appreciated to shoot at the highest setting magnification unless for some reason (like hunting groundhogs under 50 yards) there is a NEED to change. Keeping the same magnification and returning to the same position on the scope are extremely important to precise shooting. I scope for a number of SWAT team members. They never bring their heads away from the scope when shooting. They operate the bolt with their heads glued to the rifle. Finally, do not try to save money on your ammo if you want great results. Why did you buy a Kimber and then want to use inferior ammo? A person can sometimes do better in buying a little less rifle, get strong rings, a little better scope with higher magnification, and use only premium ammos or hand-load if you know what all is involved in target reloading. Then, shoot and shoot and shoot. Learn the ballistics of your rifle and ammo. There is no way to short cut this step. One other bit of advice from SWAT teams... Do not clean the accuracy out of your rifle. I mean a bore snake run through a few times is used. No scrubbing metal brushes unless a rifle starts to show signs of accuracy problems. At the end of the season clean a little better and never put a rifle away without spraying it down for rust prevention. I have learned these things over the past 40+ years of hunting groundhogs in Ohio. For groundhogs (some call them woodchucks) a rifle has to be pin-point at 100 yards or there is no reason to even try 300-600 yards shots. I have made only one 600 yard shot on one over the years. The only reason it was possible was a combination of perfect prone position, no wind in late afternoon, and it was a farm we hunted a lot and we had used a rangefinder to determine exact distances everywhere on the fields. If you are a serious varmint hunter, during the early afternoon when nothing is out much, take the time to map out ranges of all the locations you hunt at. It will make your success rate go way up because distance can really ruin a good shot. Do the extra work and keep good written records. When you miss a shot (and we all do) analyze why you missed and record it. Did you hurry the shot? Lost your concentration? Didn't notice a cross wind issue? Learn the ballistics of cross-winds for long shots on small targets. One of the best shots I ever made was only 200 yards long, but it was on a day with a 30mph crosswind. That meant I had to check my charts and shoot where the groundhog wasn't. It is tough to to that if you do not know your rifle and ammunition completely and then to trust the numbers. If you have a good rifle and ammunition learn to shoot it and watch trying to change. A newer rifle and new gimmicks do not guarantee success. The rifle only shoots as well as you pull the trigger at the right time. PRACTICE!