Is there any point in using both rifle and pistol?

I'm currenlty playing a sneaky sniper. I'm level 27 and have been experimenting around what kind of weapon loadout I should use.

Currently my "main" weapon is a sniper rifle (of some sort) for long distance and a rifle for medium to close encounters. For RP-value I've also used pistols, primarily when fighting indoors. So basically, I have three types of weapons: sniper, assault rifle and a pistol. RP aside, it just seems rather redundant to have a pistol even for very close battles when my current rifle (All American) seems doing the job just fine for those moments when a sniper rifle isn't really viable.

So basically: Is there really any point in having both a pistol and a rifle for closer fighting?

Pistol? Rifle? Why not both! That Gun is my sidearm of choice, and it fires a rifle round, which means your ammo can be shared between your pistol and your rifle. It does very good damage even into the mid- and late-game.

However, one advantage to multiple weapon types is fully using your available ammunition. You'll come across many different types of ammo, and sometimes you might be low on 5.56. Having a backup weapon that fires something else might be good in these cases.

Another thing to consider is if you want a sidearm that has a silencer. I like Sleepytyme for this, which is a SMG that fires 10mm rounds. It does decent damage and the silencer means I can stay sneaky even in close quarters. There are pistol-type options available with a silencer if you're hell-bent on using a pistol.

Rifles are also not holdout weapons, which means you can't take them into casinos and other "weapon restricted" areas. Many 1-handed weapons (including Sleepytyme, but not That Gun) are holdout weapons, though.

If you're happy with the All American, and none of these concerns apply to you, then I don't really see any other need to carry another close-quarters weapon.