I'm sorry, but I think that would be the absolutely wrong thing to do. You will be destroyed on the taxes.  You will have to pay the full tax at the time of withdrawal plus another 10% on the pretax total.  You could loose 40% or more on the current value.  Just move your 401K funds out of the market and into cash funds or some other low yield, low risk setup.

Cashing it out only makes sense if you need the cash now for immediate expenses/consumption. Otherwise you are going to pay quite a bit in taxes.

It is probably better to use that 30-40% tolerance for loss and put it in managed funds designed for very-low risk,or even a fund designed for bear-market/shorting strategies. If gold appeals to you, you should be able to buy it without cashing out to buy the physical metal--or taking the tax hit. It is unlikely any losses will surpass the tax hit you are comfortable with, and you will still have possible upside.

Dollars in hand might make you feel more safe in the short term but, emotions aside, that is just a 100% allocation of your savings in a single instrument. Probably a very poor instrument if the dollar breaks further as many are concerned it will.

Talk to a professional or do research yourself. Going with your gut isn't wise unless you understand the various options available to you. Good luck.