Terron Armstead, a 306-pound tackle, runs a jaw-dropping 40

Unless you’re a hard-core draft junkie or a fan of Arkansas Pine-Bluff, you’ve probably never heard of Terron Armstead. But he just did something unprecedented at the Scouting Combine. Armstead ran his 40-yard dash in an unofficial time of 4.65 seconds, which is stunningly fast for a 306-pound offensive tackle. NFL Network’s Mike Mayock said…