I just found MY personal holy grail and bought it! A Green Mountain LRH .54 Cal drop in barrel. This is the first one i have seen in nearly 2 years of looking, calling, etc. Some questioned if these had even been made or not? In all of my searching I couldn't even turn up a picture of one, i have checked ebay, and the gun sites nearly everyday, i feel like i hit the LOTTO tonight! This barrel has truly been like a Ghost hunt