I'm sure there's some engineers here
I rushed over as soon as I wanted to
I calculated the loads caused by rifling torque in the stress analysis of a revolver I'm prototyping:
200gr
D = .357 bullet
C = 1:16" twist
P = 90,000psi (this was for a proof load)
The component of force (F=P*A)
in the radial direction, (F*r=T)
along the rifling angle (R=atan(D*pi/C)) (I assume no bullet rotation for easy and conservative torque calculations)
gives a net torque (t=T*sin(R))
calculated as: ~114in-lbs or 9.5 ft-lbs **correction noted--t'anks Jamo
(my design calcs are in inches & pounds so I still good *whew!*)
Now, this is just for an instant, and much of this torque impulse is dampened by the weight of the gun and shooter. But the value is proportional to chamber pressure and bullet weight, and increases faster than that for radius and rifling angle. It is inversely proportional, however, to gun weight and grip distance below bore axis.
From shooting light to heavy loads in my TRR8, I've come to understand the designs of the different grips out there:
-The old Bisley puts your hand so far below the center of mass of the pistol that you easily resist the barrel torque, and causes recoil torque to be more pronounced (muzzle flip)
-A closer-in DA grip like mine resists recoil torque much more, pushing the hand straighter back, but the shorter bore-axis grip location magnifies torque more. If I screw up and don't hold the grip firmly enough, my wrist is very noticeably torqued as it rotates back (almost painfully, once)
-The only other grip style I'm aware of is the Chiappa Rhino which is nearly in line with the bore axis. Very little noticeable flip is seen when it is shot, but I'll bet hot n heavy loads in that light aluminum frame will twist the shooter quite a bit.
At the end of the day, any twist force is dwarfed either by muzzle flip or straight recoil forces, and is hardly noticed in most cases. I'd bet it's more of an issue for folks shooting for fine-tuned consistency or speed with large, fast loadings like 44mag or higher
. I'd also bet that the human arm is better at resisting torque in one direction than the other (which may or may not be the same ideal direction for reducing the Coriolis Affect. I doubt that troubles many pistol shooter, though
)
TCB