Why do you think that penetration was problematic with the bore guns? Do you think rifle weight 9 to 10 lbs for a nitro gun vs 15 to20+lbs for the borerifle or recoil 60lbs for nitro vs 200+ for the bore rifle had anythingto do with the demise of the big bore guns? How about the better trajectory of nitro guns making those cartridges more versitle and enabling one to make longer shots on a larger variety of game? The nitro cartridges were also chambered in a larger variety of guns, bolt actions ect and were able to shoot a variety of projectiles. Yes for alot of reasons modern guns and ammo out classes the old warhorse blackpowder bore guns but their effect on game is any thing but fantasy.