Chrome plating is harder than any steel barrel ever made. this means that if you have a steel barrel that a break-in procedure may be beneficial to accuracy. do it if you wish.
however, if the barrel is Chrome lined then there is no special shoot-in procedure that will do anything to help your gun. NONE. the chrome is simply too hard to benefit from any shoot-clean-shoot-clean regimen. dont bother.
this is good advice across the board for barrel break-in.
Good info Jack. I myself never know what to think on this subject. I hear SS barrels are different than Chromelined barrels. All the so called "match" shooters seems to think that you should carefullly and meticulously break in a SS barrel and I hear not to use copper brushes.
I am beginning this whole break in thing is just a crock of crap even for SS barrels. I used the 110 round break in method that took a good 4 hours, and my SS AR-10 is no more accurate than my SS M1A that only used a 10 minute 10 round break in method.
Also funny how copper brushes that bends and moves slowly will destroy a SS barrel but a copper bullet does not?
You bring up good points, if a barrel is lined and strong enough to resist corrosion and heat is expected to go 20,000 rounds, you better believe whatever break in is pretty much useless. If break in does help a rifle, I am willing to bet it will not last that long.