I have a near new, 400 rounds fired, factory 12" MRP 5.56 barrel along with the factory BCG. Everything you will need to convert your MRP from DI to piston. Or for the right trade, I will trade off the complete upper.
SPF to Unclecharlie216
LMT MRP 10.5" barrel and NiB BCG
KAC Upper (Will do upper for upper trade)
Daniel Defense Mk18 upper
Noveske Upper (Will do upper for upper trade)
BCM 11.5" upper