1911 Springs
My 1911 functions reliably with the standard ( 16 lbs.) recoil spring and loads as low as 3.8 grains of Bullseye. About a year, maybe 18 months, ago, there was a letter in the American Rifleman from one of the MASTER .45 gunsmiths. He said that he started at 3.8 grains of Bullseye and went as high as 4.3, with H&G's #68 200 gr. semi-wadcutter, to find the best accuracy in guns he accurized. He stated that he got groups around 1 inch at 50 yards, with some going as small as 1/2 inch. My personal 1911 became a tack-driver at 3.8 grs. of Bullseye.