I went to a LE website that was selling S&W M&P15 rifles I have never seen before. The site would sell to LE, EMS, Active & retired military, and Coast Guard. All of the rifles had the 5R 1:8 twist barrel. At the end of each SKU # were the letters LE. And, ALL of them were labeled that way.
I still like that Vikings Tactics M&P VTAC II rifle. That's a bad (donkey) rifle!