you may want to reduce the number of variables. try one powder, one charge weight, one bullet, measure groups then change one variable to determine it's affect on group size.
maybe you can talk about how the gun was cleaned, what powder, bullet cases, sizing dies, seating depth, etc, you are using. that may shed some light on what going between the time you pull the trigger and when the bullet hits the paper !
the joys of reloading !
thanks,
scatter