Several years ago I ran into a young guy at a gun show that had a barrel for sale. It was a 6mm or .243, on the 50 BMG case. He said it was the biggest diapointment he ever had. With that much powder he could not get 5,000 fps with it. The more over bore you go the less efficent the round gets, and once you go over 4,000 fps the extra velostiy get very expencive in term of more powder to get more velosity. I was going to get a .22-284 barrel put on a Savage action, but the guy I took it to talked me into a .22 on the 6mm case. He has built more wildcat and compition gun than anyone else I know and has done alot of field testing. He says that I should get 3,500 fps with and 80 gn. bullet with no problem and use less powder and have a longer barrel life. This round should still be moveing at abt. 1,900 fps at 1,000 yrds. so there is no way I`ll ever have to worry abt. the instablity of the bullet as it drops below the sound barrier.
