If you have any questions about the 5R, go to the snipercountrypx website and check them out. When you locate the rifle, check out image 4, and I think it will answer your question about 1/2" groups at 100 yards. Scott Powers runs the site , and has a wealth of knowledge about shooting in general. He is also very patient, and will be glad to answer any of your questions.
I purchased a 5R 308 from him about a year ago, and have been very pleased with the rifle. It's been very competitve in the two factory class 600 yard shoots I've attended. In only my second shoot, I finished 2nd out of 11 seasoned competitors. One of my 5 shot groups was 2.1545". I wish my other three were that good, but I was very happy with a 4.8" overall average at 600 yards.
Ken