My only thought is the non-uniformity of the brass removed with the tool and primer pocket contact area. As it seems from the pictures they are not uniform on the crimped area removed. Some could be easier to load but also possibly not standardized required support for the primer when fired in the pocket? Only a thought! And a primer crimp tool is not expensive and has a pilot to keep it true centered while removing the crimp and removes the same amount of material every time.
The Constitution is not an instrument for the Government to restrain the people. It is an instrument for the people to restrain the Government!
Today, we need a nation of Minutemen, citizens who are not only prepared to take arms, but citizens who regard the preservation of freedom as the basic purpose of their daily life and who are willing to consciously work and sacrifice for that freedom."
-- John F. Kennedy