I recently picked up a used 243 700 rem. I'm just having trouble deciding which caliber to build. I was going to stay with the 243 caliber but its not grouping well I'm going to continue working a load for the gun but I'm hating the fact of blowing money on it to make it shoot if the barrel life is gone . I would like to shoot in the 400 to 600 yardages . Thanks gents !!!