Here's a condensation of Hodgdon data, using bullets that are reasonably comparable. Whether the bullets are jacketed or cast is denoted by a J or C after the weight, since they have slightly different pressure characteristics:
.44 Magnum, 8.275” barrel:
240J 1582 36,200
270J 1439 38,300
300J 1325 38,300
325C 1368 38,100
330C 1350 38,800
355C 1247 37,900
Average pressure 37,933
.45 Colt, 7.5” barrel:
240J 1532 30,000
260J 1374 30,000
300J 1203 29,800
325C 1266 27,400
335C 1240 28,000
360C 1167 29,800
Average pressure 29,167
Please note the .44 Magnum's test barrel is longer than the .45 Colt's. I don't know how much effect this has, but it has some.
I tend to trust Hodgdon's data far more than many other sources, because its taken with really professional equipment, by real professionals.
