Hi Nitro,
Go with the following drill:
If it is 3xD go with Guhring series #5510
If it is 5xD go with Guhring series #5511
The drills have Guhring's Firex coating which kicks but in these types of steels.
Since you are drilling in to a convex surface you will want to reduce the feed rate by 50% as the drill starts in to the shaft. You will want to do this for about .100" in to the part. You will have to straight "G" code this and get out of the G81 unless your control has a macro to handle this.
You can start at 4000 RPM with a feed of 44 IPM. Again, slow down to 22 IPM for .100" depth as the drill enters the part. Do not use a spot drill. These drills are self centering and do not require a spot. The through coolant is very important.
Have fun.