Actually, the primary reason for chroming lining the bore of military rifles is to increase the service life of the barrel. Corrosion resistance and ease of cleaning were secondary benefits. A chrome lined bore will not resist corrosive salts indefinitely. While it buys some time, the misconception that a chrome bore is impervious to corrosive salts is inaccurate. Regardless, the US stopped using corrosive ammo well before the M16 came into our armories.
People don't chrome match barrels because they want the best possible accuracy vs. protection from high round counts and long shooting strings.
The primary reason of chromeling in a
rilfe barrel is to ensure proper wpn functioning in adverse climate - a rusted chamber is no go. Any metal will rust - go out on an exercise in rain and come back to the armoury, any bare metal turns orange overnight.
The issue of longvity only applies to MG barrels - the spec of M16 only calls for a 6000 rounds testing of acceptable accuracy. The spec of M249 calls for a 10,000 rounds endurance test to be fired in bursts. A barrel does not need chromelining to meet the M16 spec for barrel life. The US military does not seem to have any mid-life upgrade. Every year they just buy more new weapons and trash the old ones.
This debate will go around around around and around. Therer is no mysterious proprietary steel out there. It is just a matter of picking the steel you want based on price and supply. One can easily figure out the "trade" secret by doing metallurigical analysis.
Is chromelining or some other corrosion treatment preferred - yes definitely.
On the other hand, is it absolutely necessary now? Probably not - if a private or corporal can maintain a DMR with a SS barrel, anyone can do.
If HK put a Lothar Walter SS barrel on the MR223, I suppose many people will just simply shut up. However, if they put a semi-match grade CHF barrel on their rifles, people will scream for chromelining.
At the end of the day, life is full of trade off - buy a properly designed and fielded HK 416 derviative with non-chromelined barrel or some other weirdos like LWCR that seem to be perpetually being beta tested by customers.
