Originally Posted By BoovarBjarki:
Originally Posted By 1811guy:
BCM has ion bonded barrels. Much better finish IMO.
90 rockwell hardness - nearly impervious to scratching. Highly resistant to corrosion and galling. Natural lubricity. The finish becomes part of the barrel material itself; will not flake or peel off (it is actually a steel treatment and finish in one). The finished metal is only 5 microns thick - not enough to affect tolerances on the barrel with other parts (upper to barrel, gas block, muzzle device). Is also very uniform in appearance.
Melonite (also known as tennifer as seen on Glock slides) is also a steel treatment but does not produce the hardness ion bonding does. It also does not change the color since it is only a steel treatment. Melonite treated parts generally require a finish over it such as black oxide or teflon.
The downside is that ion bonding is more expensive than melonite. I am not saying that Melonite is bad, just that ion bonding has distinct advantages (aside from the cost).