Target shooters . . . HELP ME PLEASE!

[muffett.2008]

Even though it's only a carbine, your groups appear to be either climbing or dropping, ocassionally getting a diagonal string.
In order to ascertain which it is, you will need to plot your shots for a couple of groups, from 1st shot to last, but not withstanding, if your group climbs as the barrel heats up, you have a bedding problem, diagonal strings are caused by either bedding and pressure points on forewood, muscleing (NOT ORIENTATING THE TARGET) or too tight a sling. This may be pulling the forewood sideways and touching the barrel. If the group dispersion is dropping, you are changing your head position by crawling up the rear sight, this reduces cheek tension on the stock and allows the butt to climb fractionally.
Its all about consistency, only make small changes when you are sure that the last one has not made a difference, if it has, and it is'nt a good one, go back a step and try something else.
There are to many variables when you talk about a firearm that was'nt really built for accuracy.