Calculations of Bauschinger-modified residual stress in autofrettaged tubes using a simple elastic-plastic model based on the Hill method are compared with neutron diffraction measurements of hoop residual stresses in sections from a swage-autofrettage cannon tube. These residual stresses combined with pressurization stresses are used to describe tube yield pressure and fatigue lives, for comparison with laboratory measurements from cannon tubes from recent publications and new results. Gun steels in the yield strength range from 1000 to 1400 MPa are considered. Results from neutron diffraction measurements show a significantly shallower depth of overstrain in a swage autofrettaged tube compared with that predicted from earlier work with hydraulic pressure autofrettaged tubes, for the same amount of total bore hoop strain. This difference between depth of overstrain for swage and hydraulic autofrettage is incorporated into calculations of yield pressure corresponding to a small amount of permanent strain on the tube outer diameter. Comparison is made with measurements of yield pressure at the same amount of permanent strain. Comparison between calculated and measured yield pressure is good, suggesting a simple design method. Calculations of fatigue life using the classic Paris method compare well with measurements from cannon tests, once Bauschinger-modifications are made in near-bore hoop residual stresses and the difference in overstrain between swage and hydraulic autofrettage is incorporated in the model calculations.