Hi Twobobbwana,

I think for the most part you will find the wall from the lump slots to the cocking limb slot's to be thicker on a rifle than a shotgun.From the face to the back of the action has more meat and then some are bolstered aswell so the strength is added from the face to the flats.The rifle action's are thicker everywhere which also has the added advantage of adding weight.If the action's to light it will knock itself apart aswell as knock your teeth out when you shoot it.The back action locks mean you don't need to cut the outer sides of the action away for the lock bed's,again adding strength.The crosspin's tend to be slightly larger diameter and the gap between the lumps is slightly more so that the draw has the strength in it to hold the barrels down.
It's really important that the rifle is carefully jointed as if it bear's only on the crosspin and not on the draw,the action will stretch leaving the barrels off the face.On a shotgun you can get away with not having a hard bearing as the shock through the action is nowhere as damaging as a rifle.In saying that it's still important that the bearing is thereabouts.Some better quality rifle's have detachable draws which allow's the draw bearing to be restored after a rejoint.
I would suggest that anybody interested in these things to compare photo's from the internet as there's plenty out there.Even without specific sizes,comparing photo's shows the obvious differences between the two.