I have a ruger p-90 45 acp that is 13 or 14 years old. This pistol shot great its whole life until very recently. Out of the blue this gun started shooting about 3 inches low @ aprox 7 to 10 yds. I have shot thopusands of rounds through this gun, and know it very well. It is maintained religiously. I have a 12 lb recoil spring from wolf that I decided to try in it, and it did not seem to affect the accuracy. I also have a hot load kit that has a guide rod and very stiff recoil spring. with this in it it seems to shoot very close to poa. But the sprng is so stiff that it is difficult to rack the slide. Is anyone familiar with this gun that may have some ideas as to what is going on?