AR Barrel Brake In

Chrome lined barrels are dull after the plating process and it takes breaking in the gun before this lining is shine. I called Bushmaster and the two barrels they make chrome lined and stainless barrels. For stainless steel fire twenty rounds cleaning between each round with a solvent. For chrome lined it will take about 100 rounds before it breaks in but if you use a solvent it will prolong the break in period so use a dry patch. DPMS suggests for all their barrels Chrome, chrome molly, melonite, etc. for the first 25 dry patch after each shot. Then dry patch after each 10 shots out to 100 this should complete the breaking period.
 American handbook on Guns Ammo and Freedom