I have a Sport with the Vortex Strikefire red/green dot. The Strikefire and the iron sights co-witness perfectly. It's accuracy to 100 yds with this set up is incredible and even more incredible the closer the target. I want to get a scope for longer distance but so far I'm having too much fun the way it is. Buy the Sport, you won't be disappointed!
Hi guys. I just thought of adding to this thread about the M&P 15 Sport. I picked up mine [my first AR] end of July this year, had 500-rds thru it so far and had a couple of double feeds. I suspected the buffer assembly is too light and the spring might be too weak - considering a Spikes assembly in the future. I mounted a Nikon P-223 on a 1" high rings [get the 1/2" riser if you go this route to be able to keep the rear MBUS and to be able to see above and over the front A2 sight], I replaced the cheap plastic handguard with ADE Advanced carbine length quad rail - I just want to keep the A2 front sight to keep the old school look. Overall, this entry level AR is fun to shoot at the range. I don't plan on rolling in the desert so I don't really need the dust cover and FA wouldn't have helped me with the double feed anyway - found out that I over lubed it way too much that the oil was dripping into the mags making the cartridges too slick and decided to jump into the chamber two at a time. Cleaned out the lube, never over lubed it again and it was flawless ever since. I love the iron sights but my old-worn-out pair of eyes is not cooperating with the old age anymore, hence, the Nikon. I am going to build another one in the future when time comes and of course with the approval of the supreme commander - my wife, that is. My only child is handicap and somewhat limited with the use of his right hand [he learned how to use his left] but with the Nikon on, shooting with his left, his groupings were min of .5 - 1" @100 yards which is amazing, but then again he has better eye sight than his old man.
Send some down range and as always, be safe and have fun.
I suspected the buffer assembly is too light and the spring might be too weak - considering a Spikes assembly in the future. I mounted a Nikon P-223 on a 1" high rings [get the 1/2" riser if you go this route to be able to keep the rear MBUS and to be able to see above and over the front A2 sight], I replaced the cheap plastic handguard with ADE Advanced carbine length quad rail - I just want to keep the A2 front sight to keep the old school look. Overall, this entry level AR is fun to shoot at the range. I don't plan on rolling in the desert so I don't really need the dust cover and FA wouldn't have helped me with the double feed anyway - found out that I over lubed it way too much that the oil was dripping into the mags making the cartridges too slick and decided to jump into the chamber two at a time. Cleaned out the lube, never over lubed it again and it was flawless ever since. I love the iron sights but my old-worn-out pair of eyes is not cooperating with the old age anymore, hence, the Nikon. I am going to build another one in the future when time comes and of course with the approval of the supreme commander - my wife, that is. My only child is handicap and somewhat limited with the use of his right hand [he learned how to use his left] but with the Nikon on, shooting with his left, his groupings were min of .5 - 1" @100 yards which is amazing, but then again he has better eye sight than his old man. 
