I'm gonna go with the agreement that this thread is assinine. It's almost like saying 'Oh I need to go accessorize my gun with this thing!' only in a more weird disjointed sort of way.
Unless you have an actual kit specification in mind, and no primaries share magazines with their sidearm (I'm going to exclude the very few that do like the Mk.1 Carbine) you might as well say 'Marushin Derringer' since it's easiest to handload should you ever want to change ammo between your AR and your handgun ala-John Mclane.
But if we want to say the ultimate match...
Everything goes with the Digicon Thompson Match 13" Defender. Why? Because it's hand-loaded, shell-using, fires faster, farther and harder and may in fact be larger than your primary.
Or an Aquamarine-Revolver. Shoots Weird Photos every other shot.
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