And you did not even address the most important part of 'felt recoil'!!!! That is the time, usually in milliseconds, that the energy , foot-pounds' is delivered.How much recoil can you comfortably shoot before accuracy diminishes for your preferred cartridge?
The answer will of course vary, sometimes simply due to shape/fit of a rifle stock, whether it is padded, whether you’re firing a bolt or semi-auto action, etc. Plus, hunters will often describe certain cartridges as having “sharp” recoil while others have “push” recoil, which may be a felt response to powder burn rate and/or cartridge capacity. For example, the 416 Rigby is typically described as a push, compared to the 375 H&H which can be perceived as more sharp.
All the same, recoil calculations can be helpful as a broad indicator of impacts on the shooter resulting from different cartridges. Recoil calculation factors include bullet grains, muzzle velocity, rifle weight, and case powder charge. Rifle weight tends to be the dominant factor, followed closely by muzzle velocity, then bullet weight and powder charge. Here is a link to the SAAMI technical paper as a PDF file regarding gun recoil formulae: https://saami.org/wp-content/uploads/2018/07/Gun-Recoil-Formulae-2018-07-9-1.pdf
Gun recoil is typically measured in foot-pounds of energy. The proper term is “pound-foot” but the colloquial “foot-pound” is so commonly used it has become ubiquitous. The understanding of foot-pounds, however, may not be as widespread. In short, a foot pound is a measure of energy; specifically, the amount of energy required to lift a one pound object one linear foot. [Sidebar: Even less understood is mechanical horsepower, also measured in foot pounds of energy, but in consolidated chunks so that one horsepower is the energy needed to lift 550 pounds one foot in one second, or by its original calculation, 32,572 pounds one foot in one minute.]
Let’s say you fire a 168 grain 30-06 Springfield bullet in a case with 56 grains of IMR 4831 producing a muzzle velocity of 2,720 feet per second. Your rifle with scope and loaded magazine weighs an even nine pounds. In that scenario your projected recoil would be 18.43 foot pounds of energy. If your rifle is much lighter, say 7.5 pounds all set-up, then your recoil with the same bullet weight, powder charge, and muzzle velocity increases to 22.12 foot pounds. That 20% reduction in rifle weight translates into a 20% increase in recoil energy... if you’re thinking there is a 1:1 correlation there, you’d be right.
The general rule of thumb is that shooter accuracy begins to drop when recoil goes above 20 foot-pounds of energy. Needless to say, that is not a hard and fast rule for every shooter, thus the generalized question with this post. Following are some examples of average recoil energy using average charges and average muzzle velocities for different cartridges and rifle weights:
View attachment 170977
So given that there can be many variables, just as a broad indicator how many foot-pounds of recoil energy would you say is your accuracy limit, and for which preferred cartridge that you shoot?
That is the difference in the recoil between a shotgun and a rifle. The 'sharp' (fast) recoil you get from a rifle is because the gasses (mass) leave the bbl at 5,000+ fps and most have two to three times the powder (mass) than a shotgun which cause the recoil to happen faster than the shotgun which has less 'gases' (mass) at a lower velocity. The projectile is the 'push' as that is lower velocity but more 'mass'. Basic physics.