I don't see suppressive fire being of use. You would have to have a squad with you to suppress fire while you move,then you suppress while they move.
Whatever rifle is used,a person will need to fire accurate shots,then move,take cover and fire again until the escape/evasion is successful. If you have more than one eg. yourself, then the EE will be easier to accomplish.
The trick to using your rifle,is to be able to shoot it well enough to avoid being in close range of your adversary,eg. less than 200 meters..if you can stay 300 meters away from the enemy,and bring accurate fire from there,you will be much more likely to escape,or even eliminate the opposing force.
That is why I prefer a .30 caliber round. My personal choice is the .308 in the M1-A, but that is just the rifle I'm used too,and know it's capabilities.The thing is to know your weapon,what ever you are using,and be able to shoot accurately to 500 meters.
My feeling is if you are in pistol range of the enemy,something has gone dreadfully wrong..