I also have a pair of ear plugs that are connected buy a plastic band that goes around your neck... But the problem with these, is the plastic band bumps around and amplifies the sound back to your ears and its very noisy.
The only problem with the M&P AR15 Sport is finding one in stock.
Just back from my second range trip.
No problems with the M&P-15 Sport II mechanism at all. 100% success at getting it to digest both factory and handloaded ammunition with bullets weighing from 45 to 60 grains fed from plastic, aluminum and steel magazines.
My problem was with the factory-supplied MBUS rear sight. Suffice it to say that after range trips in October and November, I couldn't ever get the sights adjusted properly; the rifle was consistently impacting lower than it's point of aim.
I replaced the MBUS sight with an M16A2 style carrying handle/rear sight and within five three-round strings, I was shooting groups at 50 and 100 yards that could be covered with a quarter and at 225 yards (I don't have 200 yards), the groups were within 2 inches.
So, my experience is that the Magpul MBUS sight is the wrong size and so doesn't work. When it was replaced, everything was quickly sighted in and the rifle worked fine.
Been using these for shooting and motorcycle riding. Very effective and comfortable.
Google: Radians Custom Perfect Fit Moldable Earplugs
Available on eBay and Amazon
hugh