Chamber Length

[Bruce Day]

Recoil is:

(wt of shot x muzzle velocity + 4700 x wt of powder charge) squared

divided by

64.348 x wt of the gun in lbs.


So, if you want less actual recoil, increase the wt of the gun, decrease the weight of the powder charge or decrease the shot charge. Chamber length or pressure is not in the formula and has nothing to do with actual recoil.

If you want less felt recoil, get a gun with a straighter stock or add a recoil pad , slip on or fixed.

Pressure in the barrels is a different formula. One can easily look up from p.515 TPS what Parker intended for service loads for the gun. For example, a Winchester 20ga 7/8, 2 1/2dre load results in pressures slightly below the Parker determined service load. Tables are provided in TPS which show the loads that Parker recommended for various weights and gauges of guns. A person can also determine commercial load pressures by backing in reloading data. The belief of short chambers creating high pressures was debunked by Sherman Bell in his DGJ Finding Out For Myself series by using actual testing using strain and pressure gauges and engineering analysis.