mass bullet using a heavier charge of the same propellant to significantly greater muzzle velocity; nevertheless, we compared those two guns and we all agreed that his 223 chambered gun kicked harder – in the sense of sight picture disturbance – it was easier to see impacts at close range when firing the SMc chambered gun!
This would seem to be an impossible result until one considers that what disturbs the sight picture the most is initial gun recoil – that recoil that occurs in response to initial bullet and unburned propellant acceleration into the bore. Since the SMc design does a better job of trapping unburned propellant in the case, with these particular loads, less total mass (bullet plus unburned propellant) initially accelerates into the bore in the SMc gun. Hence, initial rearward gun acceleration (when gun is least tied to shooter and so he is least able to control gun movement) was comparatively reduced with the SMc.
Third, that despite a noteworthy performance edge, the 5/35 generated no more barrel heating than the 223. Again, this is a direct result of SMc design efficiency, more energy is converted into bullet velocity and less into barrel heating, which is a very good thing indeed.
Further
Improvements
The surprising velocity potential of the relatively small
5/35 case (equivalent to 35 grains of water usable capacity,
which is comparatively similar to the 22-250, in terms of cross-sectional
bore area to case volume), this chambering leaves little to be desired
in the performance area. In order to achieve a useful increase in
performance it would be necessary