Hey I have one of those same 257 Roberts 700 ADL synthetis rifles also. When I bought it I picked up one bnox of Federal Premium 120 grain Nosler partition shells. The first day out at the range, I shot a three shot group just under 1/2 inch .40 in fact. The only problem is that My handloads will hardly ever beat that mark. It shoots Ballistic tips and Partitions well under an inch and Barnes X bullets of 100 grains about the same. I shot a deer last fall with the 100 grain X, a big Mule deer doe. She went down like a ton of bricks. Love that 257 Roberts. I saw one of those in the Remington pump last year but they wanted 750.00 for it. I had to pass.