This is the sort of question that should have been settled 35 years ago by the time the CBA was 5 years old but like Scearcy I have never seen the results of a well controlled test that gave hard evidence one way or another. Why don't we make it a forum project to gather data and see - does it hurt accuracy of the CBs, if so how much, how much copper fouling does it take to do how much damage to accuracy (there may be a difference for a heavily fouled old military rifle and a CB rifle that has had 20 JB shots through it) bore roughness may, or may not affect the outcome.
We may not be able to pin it down to a simple definitive answer but we should be able to learn something about the issue. It's another excuse to shoot and help keep us out of the bars in the afternoons. This may or may not be as interesting as lobbing CBs and a paper coyote but it won't take a 200 yard range.
Mitch has already done some experimenting and if he can find some of his old notes that would be a start.
Lotech make a good point it may depend on the rifle as well as other factors but pinning it down a bit would be a contribution to what we know about cast bullet shooting beyond old hand-me-down pronouncements.
Wooters was a smart guy so I am betting that he was right if somebody offers the right odds, but let's either support his opinion or cast a bit of doubt on it.
If we get enough data to propose conclusions it would make a good TFS article giving the results a bit of durability instead of vanishing into cyberspace when this thread ends.
How about it? Any skeptical or curious shooters without a winter project?
To kick things off, I will produce the results of a short test -- clean bore -- twenty shots with CBs -- no cleaning -- 20 shots with factory level JB loads -- no cleaning -- 20 shots with CBs (from the same lot as the first 20 CBs.) These will be fired through a modern cold hammer forged barrel that is quite smooth, but not lapped. I won't promise exactly when because it it too darned cold for me to shoot some days here in the high desert.