When they first met, Wrench certainly had the upper hand on the Hidden Knowledge that was guns. As it stands now, his immediate answer is a more confident:

I'LL TAKE THAT FUCKING BET.

For the winter holidays, Claire got him a book on more modernized weapons. In it, a few dedicated chapters on firearms. He's never fired one himself, but he's got a rudimentary understanding on how they work now. Their purpose, the principal behind their function. Certainly he'd not be as good of a shot as anyone with any experience, but he's got enough of an idea not to fucking shoot himself. They are, as far as he can tell, the next stage that comes after a hand crossbow — but packed with black powder like a canon, firing projectiles at a similar scale.

He respects their killing power, but not necessarily the cowards that would elect to depend on them over a sword.

Rude as he is, he's no intention of swatting the poor bastard as he reaches for his dropped weapon. He indicates to it lazily with the tip of his own, nodding Wrench on. Pick it up, by your leave, he'll strike no blows for it.

Once Wrench has it in his hand, Sandor holds his own out to demonstrate.

LIKE THIS. FIRM GRIP. DON'T GO WAVING IT AROUND LIKE A DANCING RIBBON, OR LIKE A BOY CLACKING STICKS PLAYING KNIGHT. AT YOUR SIZE, YOU'RE LOOKING FOR POWER AND LEVERAGE, BUT YOU'RE STILL SPRY ENOUGH TO BE QUICK ABOUT IT.