I went out on Monday with my Ruger 308 American, my best group was Hornady 150g reloads which shot at just under and inch at 100 yards but believe me I had a number of 2-3 inch groups as well. This was my first time shooting this rifle so it is not even close to being broke in and the temp was in the mid 80s. Add to this I only get to the range 6-8 times a year and you get the picture.
Sometimes it takes time to work up a good rifle.
The 243 is a very good for deer, I used one several years ago when I was recovering from back surgery and did not want to practice with my 30cals and it worked great!
And the price on these American rifles is very good, I paid $379 for mine, with that price you really can't go wrong