mrawesome is right - most factory rifles these days have pretty long leades. It doesn't always have a negative impact on accuracy though; my most accurate rifle shoots <1/2 MOA and I'm a long way from the rifling. With some bullets I can't even get inside .040, but they still make tiny groups. I have experimented with a dozen different bullets and OALs with that rifle, at the end of the day it makes very little difference (if any), so I just load to mag length so I'm not forced to single load rounds.
By all means experiment with it as you can, but don't become too hung up on it. It doesn't always matter that much.