It is a Colt Model 1909 that at one time was worked over by Pachmayr, which specialized in fitting guns up for target shooting. It has probably been rebarrelled with a target barrel, thus removing the Colt markings.
Unless the caliber has also been changed, it will fire the .45 Colt, although the correct cartridge, no longer available, is the .45 Cartridge, Model of 1909, which has a larger rim diameter than the .45 Colt.
Jim