Clean:
Clean any Cosmoline, or any oil off your firearms and parts that was applied during shipment.
Apply light lubrication:
Use a light coating of lubricant after each cleaning, being careful not to over-lubricate. Follow manufacturer's recommendations: Some manufacturers provide specific break-in procedures in their manuals. After firing a certain number of rounds (typically 50-200 rounds, but it varies by manufacturer), clean and lubricate the firearm thoroughly.
Consider the "5 x 20" method:
Some shooters recommend firing five cycles of twenty rounds, followed by a thorough cleaning and re-lubrication after each cycle.
Important Considerations:
Not all firearms require a break-in...
Some firearms, like AR-15 rifles, may not require a formal break-in process and can function well right out of the box.
Break-in can be subjective:
The number of rounds and the intensity of the break-in process can vary depending on the firearm and the shooter's preferences.
Don't use special ammo:
+P, Hollow point, or any defense ammunition is not recommended for usage during the break-in period.
Don't over-lubricate:
Too much lubricant can make parts sticky and reduce reliability.
Listen to your gun:
Pay attention to how the firearm is functioning and make adjustments to the break-in process as needed.
Consider the purpose of the firearm:
If you are using the firearm for competitive shooting, a more rigorous break-in process may be warranted to optimize accuracy and reliability.