I just got an M&P 10 on Sept 30 when many MD stores were staying open late before SB281 took effect on Oct 1 (although this rifle is still unregulated.)

I had bought this scope to play with on my AR but decided to put it on the M&P 10 for now:

Primary Arms 1-6X Scope with ACSS Reticle
$249.99 plus mount