bullet seating

[kt]

now in these fancy weapons i cant see this being as much as an issue when seating a bullet on a pellet, but i have seen ramrods advertised that have stops on them so you can always have the bullet exactly seated at the same exact spot in the barrel. could something like this possibly be worth investing in? Usually i can put 5 under 2 inches at 100 yds, but occasionally (rarely) one will jump out and make the group 4-5 " across, could it be due to a slight difference in bullet seating? i just mark the ramrod for now?
kt