Solve This Military Problem

It's age old.  And the Army is sorta dipping into it again with thoughts of a new model pistol.

Rifles are effective weapons, but are too bulky to port about when you are doing non shooty things.

Pistols are portable, but inneffective.  The bullet isn't nearly as lethal as a rifle bullet, and it is much harder to be skilled enough to deploy a pistol to full potential.

So, throughout time, they try to shrink the rifle down or embiggen the pistol up, but no one has nailed that sweet spot.

How do you equip non-direct-combat types with a weapon that is both portable AND effective?  No one has penetrated this barrier.

The laws of physics weigh against you, I fear.    THANKS A LOT, NEWTON!  If that apple/gravity guy hadn't invented that cookie I'd have no use for him.  But I failed Calculus twice

T-Bolt waves a magic wand and solves it somehow...  Let's say you could solve the problem?  Wouldn't the regular old combat-type trigger-puller, tip of the spear folks, just take up this new thing?  Heh.

But the answer is simple the 1911 pattern Colt .45 is nigh perfect.  We just need to make a Colt .46.  People have been talking about this for YEEEEEEEEEEEEEEARS.  Just do it.  Bam!  Solution!  You're welcome.