.45 Colt mostly because it does the same thing as a .44 Magnum at less pressure, about 10kpsi less when both are loaded to the max.
One of the gun world's oft repeated old wives' tales. Newton's 3rd Law also has an issue with it.
Perhaps you don't understand Newton's third law. The 45 has 10% more area over which that pressure is acting, and hence at the same pressure as the 44, the 45 is going to have a greater reaction. Conversely, the 45 requires less pressure than the 44 to achieve the same velocity, a proper application of physics not some old wives tale.
The bearing surface of the 45 Colt is approximately 15% more than the bearing surface of the 44 mag, thus the Colt 45 is acting against more friction with the contact of the interior of the bore than the 44 mag. How much does that off-set the 10% larger surface area for pressure to act on of the rear of the 45 Colt bullet?
