Personally I would NOT feel undergunned with a 10 mm Glock at all. Right bullets to penetrate assumed.
May not be the best choice, but take something like a hot 44 mag like mine in a 329PD and the first shot is fine, but the follow ups are hard to control.
I've often thought of the souped up 45 like the 460 Rowland would be a better personal choice or a 10mm. Though I'd also think it fairly rare to draw the gun in time to fire, and to get off more than 1-3 shots anyway. So there is the thought that one well placed larger round MIGHT be a better choice.
The best is a heavy rifle starting at 338 win mag IMHO though a shotgun with GOOD hard slugs wouldn't be a slouch either.
