Although there is another argument for how many shots are permissible per turn/round, this one centers more on one shot if you have another weapon in your other hand.

Quote from Dave39528 >>

Normally I would agree with you completely however, in this case, that would completely negate a main feature of Crossbow Expert. I do not believe that is the intent.

Crossbow Expert grants you the ability to use your action to make an attack with a hand crossbow, and then use your bonus action to make another. It's worded in a very misleading way, but nonetheless it's false to say that it's completely negated by the fact that you can't normally hold another weapon while you're shooting the crossbow.

[Edit: to the OP:] OK. If I was to fire a hand crossbow, and I had another weapon in my other hand, and I only possessed two hands, then I could not reload that crossbow(Period)

If I kept that hand crossbow loaded as a habit, safety on (admittedly a modern feature), then I could certainly loose that bolt as an action. It is now unloaded and in my hand, and I can swing/stab/club/whatever with the weapon in my other hand, while holding onto the currently useless crossbow.

Do watcha want, it ain't gonna effect the way I play and enjoy the game.

Quote from first_rolled_a_die_in_1976>>

Whatever the rules may be, that's a hell of a lot of activity in a 6-second period of time. Having used crossbows, both 20lb hand, and 150lb stirrup & lever style compound bows, I can tell you that, aside from some auto-cocking mechanism or magic, and some form of magazine pre-loaded with bolts (conceivable, but difficult to build and should be wildly expensive), all crossbows require two hands to cock and load the weapon. Moreover, to loose a bolt, reload, and loose another within 6 seconds, may feasibly be possible with a hand crossbow, but damn difficult. Getting off two aimed shots in that time bracket would border on the impossible.

That's my real world experience. I'm new to the 5E rules, but have not yet been at a table where 2 shots per round were ever allowed, using such weapons. I didn't check the current rules, so have no opinion on what RAW allow for. 

Two things:

1. Hand crossbows have the Loading property, which means they can't be fired more than once per turn/round without special allowance. The Crossbow Expert feat removes the Loading property, and grants the ability to shoot a hand crossbow again as a bonus action if you used your action to Attack with it. Basically, you can't shoot more than once in 6 seconds unless you're really an expert (or you have some other special feature that lets you do so).
2. Hand crossbows, according to the PHB, weigh 3 pounds. Probably a fairly different experience than the 20 pound crossbow that you used, which is heavier than even heavy crossbows (18 pounds).

I see what you are saying as far as how you are interpreting it, but that is not at all how it is written.

Crossbow Expert; When you use the Attack action and attack with a one handed weapon, you can use a bonus action to attach with a hand crossbow you are holding.

This seems clearly to imply that you are holding two weapons, such as a sword and hand crossbow.

It would be negated by the Ammunition property that says you need a free hand to load it.

[Edit: to Quar1on] 20lb refers to the pull of weight of the bow, at its cocked position (light- single hand crossbow, ~3lb). 150lb, the same; medium strength, two-handed (modern) crossbow(~12lb). As for the rest. . . game logic need not agree with my opinion.

Quote from Dave39528 >>

I see what you are saying as far as how you are interpreting it, but that is not at all how it is written.

Crossbow Expert; When you use the Attack action and attack with a one handed weapon, you can use a bonus action to attach with a hand crossbow you are holding.

This seems clearly to imply that you are holding two weapons, such as a sword and hand crossbow.

What part of it says that you have to be holding two weapons, though? Here, why don't I refine the statement a bit.

Statement:
When you use the Attack action and attack with a one handed weapon, you can use a bonus action to attack with a hand crossbow you are holding.

Because hand crossbows are one handed weapons:
When you use the Attack action and attack with a hand crossbow, you can use a bonus action to attack with a hand crossbow you are holding.

Because nothing restricts you from making both attacks with the same weapon:
When you use the Attack action and attack with a hand crossbow, you can use a bonus action to attack with the hand crossbow you are holding again.

Because you had to be holding the hand crossbow to make the attack in the first place:
When you use the Attack action and attack with a hand crossbow, you can use a bonus action to attack with the hand crossbow again.

There. I just used logic to transform the sentence into unmistakably saying that you can make both the initial and the bonus attack with the same hand crossbow. If you want to find a flaw in my logic, go ahead, but you won't succeed.

Again, in the grand game of Chicken that is the PHB, implications will almost always pull out before hard rules.

There ya go! ^

I think the OP forgot that the crossbows still have the ammunition property. If you can somehow get rid of the ammunition property, THEN you can two-gun hand crossbows.

Nothing says what weapon you may be holding. It also does not say you can only be holding a hand crossbow. I would argue that the wording is such that it paints a senario where you are holding two differerent weapons, as supported by the wording of the light property. Why only use a d6 weapon when you could use a d8 weapon.

I believe the rules themselves allow you to overcome it, as do many rules in the game that allow you to do something that is normally not possible.

Please understand I am not saying that everyone has to have this in their game, just that I believe the rules allow it.

Quote from Dave39528 >>

Nothing says what weapon you may be holding. It also does not say you can only be holding a hand crossbow. I would argue that the wording is such that it paints a senario where you are holding two differerent weapons, as supported by the wording of the light property. Why only use a d6 weapon when you could use a d8 weapon.

That is the image that comes to mind when you read the feat, I agree. But the rules make it impossible, except under certain circumstances (like the Repeating Shot infusion from Artificer). The feat is still very useful, it's just poorly worded, as is the Light property.