Are any 10 ounce bar holders drilling holes in them?

I've held some 10-ounce Johnson-Matthey gold bars for a while now, and am considering taking a drill to them, simply to satisfy my curiosity. While I am not naive to assume the stories regarding tungsten-filled bars may simply be planted to discredit gold, there is simply no way to accurately assess whether the bar is or is not salted.

I can't be the only one considering this, but if anyone here has done this, I would like to know whether defacing the bar in this manner seriously devalues it, other than the weight of the removed metal. I would sell it as a 9.xxx ounce bar, were I to do so, but I was just wondering if anyone else has any experience with this.

Many thanks!

T1stO