My Forbes shoots factory Nosler ammo loaded with 140 Nosler ballistic tips into 3 shots groups that all touch at 100 yards more often than not. I am about to load my first ammo for that rifle. Should I fool with chasing the lands or should I just duplicate the OAL of the factory ammo first?

I'll be using that same once fired Nosler brass and same 140 BT. I was just going to start with 54 grns of H4831SC.