I have a Ruger1911 in 9mm that I only shoot at the range as a target pistol. I am shooting light target loads out of it and about 50% of the time the slide will not stay locked back on the last shot. I called Ruger and they told me that the stock recoil spring in my gun was 12 lb. I ordered some Wolf springs in 10 & 8 lb. I am hoping that this will cure the problem. Any thoughts on the subject?