Gunsmithing Installing Flush Cups in Manners

Best in a drill press, but I have installed a couple dozen flush cups by hand with my drill. immobilize the stock, go straight down as close to 90 degrees as you can and go slow. Don't overdrill the depth and check it often. Make sure you choose good areas for the placement of the cups
 
So no issues using a standard drill bit,
I had planned to use my drill press. I was worried about splitting or chipping the stock.
 
What is the best way to drill for flush cups in a manners stock? I have the manners that comes with CZ Precision Trainer.
I use a forsner bit in a drill press to get a precise hole with no chipping. A piece of leather works very well to protect the stock when you clamp it in the vise on you press bed so you can really hold it solid. Use C-clamps to hold the vice down, you want the work to be located well and SOLID. As others have said go on the infeed but be sure your RPM is right.

Also recommend the non-rotate style so you can index your strap but not have it twist up on you. Confirm you have the right orientation when you epoxy them in and you are good to go.