I bought a complete AA upper from AA in about 2004 or 2005. I bought a spiral brake from them and installed it myself.
The upper was about $450 and the brake was about $70.
I bought one mag from them but wanted more.
I called AA one day and Bill answered the phone. He seemed nice enough and quickly explained to me how to adapt the steel bags to feed the 50B rds.
I joined the 50B forum and found a guy selling a full case of the AA brand of 300gr Gold Dots at a super price,so I swooped them up.
Never reloaded for the 50B but heard horror stories about others expierances.
The upper went on a Bushmaster lower with a 3.5lb trigger. I was able to shoot <1.5 inches at 50yds (5 shots).
I used the gun for hogs from a shooting house and ladder stand. My max shot was about 125yds. --- SAWMAN