What is your benchmark for a "big bore" bullet?

[SIGSHR]

40 for semi autos-the 10MM Auto, e,g., 41 for revolvers.

 

[artoo]

Been with the .40 caliber on up is big bore. Don't see a reason to change now.
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[Kevin Rohrer]

Any caliber w/ a "4" or larger at the beginning is big-bore.

 

[Mike Irwin]

For me, it starts with my .41 Magnum and gets better from there.