I am reloading some .450 Bushmaster cartridges, got the brass prepped, then......realized that I do not have any small rifle primers!!! That's not working too well for me at all; not a good plan. I started surfing the net and found where the small pistol "magnum" primers could be used in place of the small rifle primers. More reading shows that there can be problems using small pistol magnum primers in the .450 Bushmaster. The rifle is an S&W lower with a custom .450 upper. I don't like varying any at all from the manuals, and....I certainly do not like the load data one gets from the internet. I have quite a few small pistol magnum primers, but again not interested in getting hurt, hurting anyone shooting with me or wiping out a rifle. Anyone have any input on this issue/question, it would be appreciated.