Colt models marked LE Only.
Do they all have chrome lined barrels?

Yes

Thanks

As does the "Civilian" Colt M4 the 6400C, in 1/7 twist.  All Colts except stainless barreled SPRs have at least Chrome Chambers - an unplated barrel is generally more accurate, but a chrome barrel requires less maintenance.  Where chrome is really important is in the full auto and "off the pavement" world.

Warmly, Col. Colt

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