Smith and wesson m&p15 upper

[Friberg_SWE]

Hi. Iam looking for an upper with 18" barrel. Can I use another brand? Do any body know what would fit whit out a lot of adjustments.

 

[bamashooter]

Most upper, lowers, parts are interchangeable with ARs. Swap uppers will be the easiest or you could change barrels. Other than re-zeroing the sights / optic, there should be no other adjustments needed.

 

[NewLiberty]

Assuming everything is made within spec, any other brand AR-15 upper should fit on a M&P lower.

AR-15 specifications are very standardized (this is not true of AR-10s), so it should swap easily.