Head - Sgt. Savage v2
Torso - Road Pig
Arms - Sgt. Savage v1
Waist - Sgt. Slaughter v2
Legs - Major Barrage

Accessories - Marauder Inc.

Hammerdown is a character that appeared in IDW issue #18 (May 2010), one of the many "we need a Joe to die so let's make up a new one just to kill him off" that we've had over the years. He's portrayed as a huge guy, presumably close to the Army maximum of 6'8". As you can see in the comparison pic with Downtown and Cover Girl (who featured heavily in that issue), he's got a substantial height advantage. His only ARAH-era parts are the torso from Roag Pig and waist from Sgt. Slaughter. The legs are Major Barrage, and the arms and head are Sgt. Savage. The cap and HK416 are both Marauder Inc. Their caps are really versatile - they're designed for smaller heads but fit this big noggin very well.