I'm running the SiCo Harvester Big Bore and it sounds great, shoots great, but I hate the mounting system. I might convert it to direct-thread. I got it only because it was the only thing in stock anywhere. Purchased sometime in 2014. I really wanted the SOCOM 338 but that was always sold out when I was in the market. I use it on a Barrett MRAD and cuts the recoil in half.