LAST EDITED ON Aug-30-14 AT 02:03PM (MST)[p]Just because the scope is already on the gun doesn't mean you are good to go as far as it is concerned. Make sure anything that should be tight is tight. However, you can overtighten the rings and crush the tube of the scope if you apply to much force. You will notice that there is always some space left on the rings (the bottom and top ring should not be touching).
And as mentioned, you want to be sure the scope is mounted right for your son. Too far back and he will get hit with it during recoil. Too far forward and he won't be able to see well when he holds the gun comfortably. Get him to close his eyes and grip the gun in a "comfortable" shooting position. Now have him open his eyes and see if he can see clearly the full scope view without moving his head much. If not, the scope may be mounted too far forward.
As stated, you want to start at 25 yards first. Get the bullet hitting the bullseye dead center. With that you will be pretty good to jump to 100 yards. I sight my gun in at 1.5-2 inches high at 100 yards. That way I don't have to think about it to 250 yards, just aim and shoot. A novice shooter probably shouldn't shoot further than that on his first hunting trip. The country you will be hunting will probably allow for shots much further than that, but I wouldn't stretch it much because you want a good experience, and wounding game is not good for a first time hunter.
And lastly, I too like Remington Core-lok ammo in 130 grain. It should do the job on mule deer. It is also realatively easy to find and not that expensive, so I would at least use that for practice. That said, in my 270 when I take it mule deer hunting, I use Hornady 140 grain interlock ammo
txhunter58
venor, ergo sum (I hunt, therefore I am)