Larry;
I have made that statement in the past about hanging a gun on the wall if it was not considered safe with 8K loads, so I am likely the one you recall saying it. An exception to this would be a gun with light a breech section built prior to the introduction of smokeless. IF in a good sound condition I would consider shooting it with Black Powder Only. Also, I have stated on numerous occasions that the rise in pressure down the rest of the barrel is only a "Slight" increase. It is not normally enough to be concerned about. The fact remains though & is really beyond dispute, that using a load with a low chamber pressure when the same shot charge is given the same velocity, does Absolutely nothing to help the forward end of the barrel.
Now before someone flames me (Again) I am well aware that pressure is pressure & doesn't care if the color is Red, White & Blue or just plain Black. However, when it comes to propellants Black gunpowder is much more forgiving of any slight errors one may make in loading & it is virtually impossible to get an overload in a standard case for the gun.
Buzz;
Max Peak pressure has nothing to do with recoil. The formula for recoil is ejecta weight which is shot weight plus wad weight plus 1¼-½ time powder weight. That 1¼ to 1½ will vary whether one is loading a light shot charge with a fast powder or a heavier charge with a slow powder. This is predominately an estimate & is to offset the increase in the velocity of the Gases as they exit the muzzle, which adds to the recoil. As an example, let's take a 3-1 1/8 load using a wad which weighs 35 grains & 20 grains of powder. We'll use a middle of the road for the powder multiplier & take it at 1 3/8. We now have a total ejecta weight of 555 grains which converted to pounds gives, to keep figures even, 0.080 lbs. Multiply this by 1200 fps & you get 96. Divide that by the weight of the gun. Let's use 6 lbs even & you get a recoil velocity of 16 fps for the gun. I find the recoil velocity to me much more useful than Recoil Energy personally. A recoil velocity of around 15 fps is mild, 16 is getting a bit stiff & if I'm going to shoot more than one or two shots I do not want to exceed 16 by much.
So, Yes, you are correct, both the velocity of the shot & the recoil of the gun are generated by pressure. Neither, however, are directly proportional to the Max Chamber pressure. This is what has confused many. That old Bug-a-Boo of thinking the max pressure is the end all of shotgun ballistics. The Max pressure is truly of importance only to ensure the load does not exceed the pressure the chamber was designed to handle. In reality, it plays a very minor role in other aspects, including velocity, recoil, the strain on the action & splitting of stocks. Ejecta weight & velocity are the important factors in all of those. Pressure is not in the formulas for figuring any of them.
Last edited by 2-piper; 06/20/19 10:30 PM.
