Two M&P's w/different markings

[florida1098]

Just wondering if there is a difference. I have two AR's M&P both brand new. One says model 15 and 5x56 ww on lower and other just has model M&P 15. Is there any difference in Caliber capability or just S&W not being consistent ?
Thanks

 

[n3cal]

Does either of your guns have any markings on the barrel? According to the M&P15 manual the cartridge designation is marked on the barrel. The manual I have (Rev:MP15_090409) covers M&P15, M&P15A, and M&P15T models. It's like a generic manual. I have no idea wheter this manual comes with all versions or not.

 

[florida1098]

Mine came with the same generic cover every model manual. On the barrel it has 5.56 NATO 1-9. The second AR I have is one I built with M&P lower and DPMS barrel and upper receiver, Bushmaster stock, DPMS trigger group, so it has no manual. Never fired either yet. The one I bought whole is the 15X, but just dry firing them, the DPMS trigger group is slightly smoother and crisp.

 

[Thomas_H]

Early M&P-15's were actually manufactured by CMT/Stag. From what I understand, Smith & Wesson now manufacturers them in house, or at least assembles them in house. Not sure if S&W mills their own forgings now or not.

So it could simply be a difference between when CMT/Stag was building them and S&W's process.