The velocity of recoil and thus the ft/lbs of recoil generated by a fire arm is a combination of the ejecta mass versus the wt. of the object it is pushing against. (Something to do with Newton). Thus a 200 gr. bullet with 5 grs. of powder has an ejecta mass of say 900 fps to make a power factor of 180. Thus 205 grs are ejecting at 900 fps of which 5/205 about 3% is contributed by the gas. If the port holes are smaller than the exit of the bulllet you have the same gas now wanting to get thru smaller holes and a supposed increase in velocity, a rocket effect. A 38 uses say 130 gr at around 1400 and 10 grs.of powder or a total of 140 grs or 10/140 or 7 %, and of course as the arguement goes smaller holes and even higher velocity. Take a 50 ca. 500 gr, and 400 grs. or 900 grs. Now the gas contributes almost 50% of the ejecta mass and porting, or muzzle breaks make a significant difference. Even if the ejecta mass of the handgun is directed a 90 degrees to the perpendicular of the muzzle bore, the mass of the ejecta is 7000 gr times approx. 48 oz or 5 grs. to 21000 or 5/21000 or 2.34e-4 very little indeed. However if you plug the ports the additional weight say 2 oz or 60 gr is 60/21000 or .0029 more mass for the ejecta to move. In short the static torque moment of the additional wt. has much more effect effect that the small amount of rocket gases. I know this will cause indigestion and many nasty e-mails.
.45 Compensators - do they really work?
in Open Pistols
Posted
The velocity of recoil and thus the ft/lbs of recoil generated by a fire arm is a combination of the ejecta mass versus the wt. of the object it is pushing against. (Something to do with Newton). Thus a 200 gr. bullet with 5 grs. of powder has an ejecta mass of say 900 fps to make a power factor of 180. Thus 205 grs are ejecting at 900 fps of which 5/205 about 3% is contributed by the gas. If the port holes are smaller than the exit of the bulllet you have the same gas now wanting to get thru smaller holes and a supposed increase in velocity, a rocket effect. A 38 uses say 130 gr at around 1400 and 10 grs.of powder or a total of 140 grs or 10/140 or 7 %, and of course as the arguement goes smaller holes and even higher velocity. Take a 50 ca. 500 gr, and 400 grs. or 900 grs. Now the gas contributes almost 50% of the ejecta mass and porting, or muzzle breaks make a significant difference. Even if the ejecta mass of the handgun is directed a 90 degrees to the perpendicular of the muzzle bore, the mass of the ejecta is 7000 gr times approx. 48 oz or 5 grs. to 21000 or 5/21000 or 2.34e-4 very little indeed. However if you plug the ports the additional weight say 2 oz or 60 gr is 60/21000 or .0029 more mass for the ejecta to move. In short the static torque moment of the additional wt. has much more effect effect that the small amount of rocket gases. I know this will cause indigestion and many nasty e-mails.