Barrel break in is not as important nowadays as many people think, but it is important to clean out small burrs and machining marks. As the bullet travels down a CLEAN barrel, its pressure and friction will do this. The best procedure is:
1. Clean the barrel, paying extra care to the throat
2. fire 5 one shot groups, cleaning the barrel between each shot.
3. Fire 2 three shot groups, cleaning the barrel between each group
4. Fire 2 five shot groups, cleaning the barrel between each group.
5. You're good to go!