My 1894CBL with 24" barrel chambered to .357 Magnum measures .5635 from barrel dovetail to top of the site. If I took out the front site I could get a more precise measurement but that should give you a close idea. I have a Lyman 66A receiver site mounted and it works perfectly with the factory front site. Mine's a shooting SOB with my own cast bullets using the Ranch Dog 359-175 RFNGC bullet which weighs 179 grains lubed and gas checked. I run it at 1638 fps with 2400 powder. Even with my old failing eyes she'll put three shots into under an inch at 50 yards.