I bought a MK2 5" bull barrel recently, and it shoots as well as my 6&7/8 tapered target MK1. While its true about the ammo I have only found that my guns including a S&W 617 shoot Wolf target, CCI silhouette, and federal game shock, better than the rest. They don't consume Remington well. All others are good also, and I have tried most brands and weights, with the exception of the winchester dyna-what ever, can't find a place that has it in stock.
Jim