Got a late start at hunting and didn't get into it until 12. Had a full handloading setup for multiple cartridges by 15. I think, if I remember right, I had 4 or 5 guns at 15, but that was a long time ago.;)
My son was shooting at 6 and helping me with reloading at 8.
At one point in my hunting career my long range rig was a sporter made by a fella named Al Biesen. It wasn't exactly a dedicated long range rig, but it shot pretty good and looked and handled fantastic.;) Alas, one of my more stupid acts in life, I sold it and went in a different "gun" direction.
Start as early as possibly and shoot until you can't do it anymore. Can't get any better than that.