This upper started its life as an HK MR556A1. I sent it off to Jayson at IGF to have the following work done to it:
Barrel chop to 10.4"
Gas block vented and gas port tuned for 10.4"
Entire barrel assembly nitrided
It has the HKparts MLOK rail on it and a Magpul vertical grip. It has a Silencerco ASR flash Hider on it currently. I can swap that for an AAC 51T FH is the buyer would prefer.
This upper was test fired one magazine when it came back from IGF. It ran great suppressed and unsuppressed.
$2150 shipped. No CC fees. Purchase here - BUY NOW AT QRF