Having a couple of options is your best bet. Padlock and chain is one, a U-lock and large cable is another. It forces the thief to need more than one cutting agent.

BTW, the old master lock didn't "withstand" the rifle shot. Rather, it penetrated the lock, through and through. But the lock didn't open (and as my uncle pointed out, it never would again after that).

Great Super Bowl Ad - Shot Lock from Master Lock - YouTube

It occurs to me that thieves might be less interested in bicycles that have no wheels. Maybe not high dollar bikes though...

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You're a daisy if you do.
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84 Euro 240D 4spd. 220.5k sold
04 Honda Element AWD
1985 F150 XLT 4x4, 351W with 270k miles, hay hauler
1997 Suzuki Sidekick 4x4
1993 Toyota 4wd Pickup 226K and counting