Powder charge is signifigant and is best quantified in the recoil velocity description of recoil. More powder means more recoil velocity.The body withstands recoil better if it is delivered over a longer period of time, ie a lower recoil velocity.

The critical components of recoil are bullet weight, rifle weight, bullet velocity and powder burned.Footpounds and recoil velocity can then be determined.

That reason is why overbore cartridges like the 30-378 or 378 Wby are so obnoxious. The have a large quantity of powder escaping through a proportionately same diameter exit hole gives a venturi effect and thus increasing the recoil velocity substantially.That HURTS more!!

The big bore shells are basically straight walled but the powder volume is a signifigant issue as anyone knows if they start burning more powder for hotter loads in their doubles.