The 33 round magazine is for the G18, a select fire “machine pistol” that is only sold in Europe to military and leos. I did see one at Knob Creek 10 years ago tho. After the second round you are trying to keep it from shooting holes in clouds. They are an NFA firearm, highly regulated, requiring BATFE papers to own. As for the mags, I guess there is a cool factor, although how cool it is having at least 10 inches of mag hanging out your G17 or G19 escapes me, but to each his or her own. I suppose for range time they cut down on reloads.