Front sight too high?

Had my 50th Ann. .357 Flat top (4.75" barrel) at the range last week. At 50 feet with a plinking load (158 gr. SWC at 800 fps) I had to raise the rear sight all the way up to hit the paper. Got home and compared it to my OM Flat top (1958 vintage, 4.75" barrel) and determined that the measurement from center of bore to top of sight on OMFT is .743" and NMFT is .845" or a tenth difference. What gives? Time to get the file out? or ?

Have you shot anyfactory standard loads from this gun? Most .38/.358 Rutgers are regulated to shoot the 158 gr standard loads.
If you want to shoot soft loads , the front sight may have to be modified.

I have a number of Ruger SA's, both old and new models, all calibers from 22 to 45. Usually shoot cast bullets around 800/900 fps area and have not had this problem before with any other.