Ya gonna need carbide drills and go slow.
An M35 cobalt alloy bit on the press would work well, but an M42 cobalt alloy bit would likely cut it like butter. High speed steel bits will lose temper at high temps when drilling hard steels and iron, but the cobalt alloy allows for a much higher working temperature and hold the temper very well. Use a good cutting oil as well and clamp the piece very well and it should be fine. Be careful though, a lot if junk companies try and sell TiNi coated buts as cobalt "like", but those won't work.Good luck!
My advice to you is simple. Inspect the material before drilling, there might be nails or knots which avoid a right drilling. Stabilize the material. Pre-drill holes. Is it the material too hard? Buy a drill more powerful. Check more tips here LINK REMOVED and have a drilling safety.