The majority of rifle ammunition military and civilian is optimized for longer barrels, when you start shortening barrel length the chamber pressure at the point the bullet leaves the barrel increases. On top of this the percent of powder burned "inside" the bore decreases creating more muzzle blast. The end result is short barreled rifles have "more" rocket thrust and blast, if you reload this can be tamed with faster burning powders that burn more completely.
I have the computer software Quickload and it gives you the percent of powder burned and the chamber pressure along the entire length of the barrel. Any rifle can be tamed with lighter bullets and faster burning powder and reducing the "rocket thrust" as the bullet leaves the barrel.
Below is a Quickload example of the 30-06, by reducing the peak chamber pressure 10,000 psi with a lighter load the pressure at the muzzle is greatly reduced to 500 psi and the percent of powder burned is 98.11%, meaning less "rocket thrust" recoil going to your shoulder.
Below a pressure trace of the .223 and 6.8 Remington SPC, the larger diameter 6.8 Rem SPC has less muzzle blast than the .223 with a faster burning powder.
As another example I was at the range testing loads in my No.4 Enfield, I was using the same bullet and different powders. I had just finished shooting 50 rounds with a fast burning powder IMR 3031 and then started shooting the next load using IMR 4350 a much slower burning powder.
When I pulled the trigger on the first IMR 4350 load the felt recoil was twice as much as the faster burning IMR 3031 powder I had just finished shooting. The burning rate of the powder affects the amount of rearward force or kick the rifle will have. What amazed me was I had just pulled the trigger on the suggested starting load of IMR 4350 and the lightest load in that box kicked harder than the max load of IMR 3031 in the last load I had shot.