If your rifle is marked M15A4 , and has the
"flying horse" on the magwell , and a white
"eagle" stamp on the front of the magwell,
it SHOULD HAVE a chrome lined barrel!
ALL Armalites except the target models have
chrome lining.-----------from the Armalite
web site---------------------------
[b]"WHY DOES ARMALITE OFFER THREE TYPES OF BARRELS (CHROME MOLY, CHROME LINED, AND STAINLESS STEEL)
Because each barrel has advantages suited to different uses.
ArmaLite's Chrome Moly barrels have excellent internal surface finishes, and offer excellent accuracy for a reasonable price. Chrome lined barrels offer excellent corrosion protection and slightly longer life expectancy, but are more expensive than unchromed barrels. In addition, the process of electro polishing the barrels, and the chroming process itself, tend to reduce accuracy somewhat. Stainless is easy to process to fine surface finishes, and provides moderate corrosion resistance.
Chrome Moly is thus used for Eagle Arms' standard rifles, for good accuracy for beginners at a low price. ArmaLite A2 and A4 rifles, in either .223 or .308 caliber normally are produced with chrome lined barrels for hard service use under adverse conditions, with stainless steel as an option. All ArmaLite match grade rifles, the Ts and National Match rifles, are made with stainless steel barrels for superior accuracy and decent corrosion resistance."[/b]