If you do not reload and are not rich - get the 610 and fire .40 S&W out of it.

If you do reload - get whichever floats your boat. You'll probably wind up with both eventually if you become a revolver guy.

If you are in the market for a first revolver I suggest you look at the following:
617 - for lots of 22lr plinking fun.
686 or 627 - .357 Mag goodness that also fires .38 Special.
625 - if you already have a .45ACP pistol, this is a fine .45ACP revolver that uses the same ammo.

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My sgntr is mor thn 30 chrctrs