Have a 50-70-750 from Mr. Whisper, and YES, it does kick like a mule. Shoots .510 sub like the 510 Whisper. Before I thought about getting a can, I had BT Tech. put a computer designed muzzle brake on it. Zero muzzle rise. A world of difference to shoot. Only shot it out to 250. Does a number on deer!
Rikky- sorry I missed your earlier post. My 300/221 load is 8.5gr LilGun under a 220gr SMK and is the one I shot at 830yrds. I have tried countless different recepies but this one works for me.