S&W M&P 15 Bayonet options

You need one of these:

http://www.cheaperthandirt.com/ARR044-7.html

Stag Arms is one manufacturer of AR type rifles.

uuuuhhhhh.....they have a bayonet lug.......

My cousin has an M&P 15, and I believe he got his hands on a Buck M9. It looks pretty sweet. not sure how practical it is though, but then again, we don't always need practicality, do we?

The point of the CheaperThan.... bayo lug is that it can be positioned correctly for the longer barrel so that a standard bayonet fits.

The M&P has a carbine length gas system and a 16" (instead of the carbine's 14.5") barrel... so you need to shift the lug forward 1.5 inches or get a non-standard bayonet.

Standard bayonets will only fit on:
14.5" barrel with carbine length gas system
16" barrel with mid length gas system
20" barrel with rifle length gas system

xx7grant7x do you see the problem here?

And what it's supposed to look like: