I'm with Cayugad on the .54 Rene shooting PRBs pretty good. But as long as you have a .50 and shooting 300 gr saboted bullets my question is why would you want to shoot them in the .54? There would be no benefit except having another rilfe. If I were you I would use a PRB or, for a lot more 'wallop' you could use a full bore conical like the Lyman Great Plains bullet.