I have used Murph's "Hosford" horizontal technique with my Manson gauge for 10 years now and find it consistently repeatable within one or two thousandths. While experimenting with other ways to hold the block end, I realized that the cord in the eyebolt lets gravity do all the pulling and that the sensor ball naturally rolls to the bottom of the barrel without any side pressure influences from fixed holds on the block end. Thanks again Murph for saving me the cost of having to buy a Hosford tool, or one of Dewey's digital ultrasounds . MP