I had the Barret and the McMillan TAC 50. We were in WV and shooting long range when a very good buddy walked up beside the TAC 50 just as I shot, it bloodied his nose and gave him a pretty bad headache for 2 days. Not sure if he got a concussion or not but I caution everyone around a 50BMG. The TAC 50 with the Big Mac stock was a very good rifle but with all the advances in bullets and powders, I enjoy my 300PRC more, so I sold both 50 caliber units. I used the 750 grain Amax ammo for both.
I always wore ear plugs and sound deadening ears over to avoid any issues.