That’s like saying it’s more deadly to get run over by a semi tractor trailer going 50 than it is getting run over by an SUV. Both are super deadly and more than enough to kill you.
Statistically, with a traditional pistol caliber, unless its a head shot, you have a 90% survival chance given immediate medical attention. Not so with a rifle round. The higher velocity changes the damage mechanics. That is why a rifle is always preferred to a pistol, and the only reason you have a pistol is to fight your way back to the rifle you never should have dropped. Unless its impractical to have the rifle of course, like while walking the mall.