If it has done it from the start and with different magazines OFF TO RUGER is the correct answer. If you only have the one magazine you might try another factory magazine.
The magazine of any magazine fed weapon is the "Number One" cause of malfunctions and especially feeding problems. And if it should be the magazine I sure would contact Ruger and advise it was the magazine! I am sure they will take care of any problem since it has been doing this since the start.
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