Stone cold-I own two 300ultramags,two 7mmstw's and a 7mmultramag and am very happy with them.However,developing and maintaining the necessary shooting skills to be consistantly accurate at distances of 400 yards or more requires a great deal of practise amounting to at least several hundred rounds per year.Since these cartridges have barrel lives limited to about 1500 rounds before throat erosion causes accuracy to diminish you must either be prepared to rebarrel them on a regular basis or have several guns of similar ballistics to practise with to prevent burning out barrels.For this reason they are not wise cartridge choices for many shooters.