Overall, the combination of less expensive 5.45x39 (for now) with adaptability of AR platform with various accessories such as sights, stocks, and forward rails will appeal too many. The inherently more accurate AR platform will further sway others. An AR chambered in 5.45x39 should not be discounted as a worthy addition to weapon collection due to flexibility of utilizing available ammunition for either training purposes or more serious applications. It will be curious and enlightening to watch how the M&P15R fares in the long run in terms of market success. Tendency might be for AR users to stick with 5.56 and AK users with 5.45 due to ingrained norms being too hard to break free from. In either event, the S&W M&P line of ARs should be considered by anyone looking into purchasing an AR platform no matter the caliber desired.