Well it's an advantage because you can identify your mistakes in timing more easily. Move up to 40 yards. If your groups tighten up immediately, which they most likely will A BIT, practice till they are even tighter. Then move back to 60 and see if they are still as tight. Just as with archery, distance transfers ANY misstep in form. You must get your timing with that particular rifle down pat. At a closer range practice, you will be able to see more easily where you goofed or didn't goof. You will be able to concentrate more on your form and timing and relaxation, rather than the target, at closer distances also building confidence. Right now your confidence is suffering and that is transferring to the shots. I teach archery quite often and this is a key element to good form.