Tag Archives: monolithic rail platform upper receivers

Monolithic Rail Platform (MRP) and Quick-Change Barrel for the M4A1 Carbine

by David Crane david@defensereview.com DefRev discovered this item at SWAT Round-Up 2003 back in November at the Lewis Machine & Tool Co. (LMT) booth. It’s called the "MRP", which stands for "Monolithic Rail Platform". While the MRP is interesting, the most interesting aspect of the system is the quick-change barrel feature. MilitaryMorons.com (a very cool and informative site, by the …

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