I'm having some problems drilling though my o1 tool steel I first tried on the handle after the knife blade had ben hardend and today I heated the whole handle past critical temp and let it cool I still can't drill through my drill bits are fairly new and drill trough my other knifes fine any suggestions.

Even air cooling a small part like a knife it may have hardened on you. Next time you are working after your forge has been used, totally heated, try to heat to critical and then leave in your forge to cool I am guessing you are using a gas forge if not then find a different method of slowing cooling. The other plan I would try is to just temper beyond hardness, such as tempering to say 700f.

Heat to critical then place it buried in vermiculite or wood ash. It's best to have a large hot bar of steel next to it to help it cool as slowly as possible. It should still be warm to the touch the next morning. Then it is annealed. Drill away. 

Cobalt Drills are a good investment when drilling alloy steels. I keep three sets to drills.  One hardware store quality for wood and casual handyman work.  A better quality of highspeed steel with better sharpening for mild steel.   Cobalt drills bought one at a time from machine shop supply houses.  The above suggestions need to be followed carefully.

I drill after anealing. I regularly use cobalt drill bits. If I find it hard to drill holes then I switch to carbide bits. Those have always worked in hardened steel for me. I keep 4 of each size I normally use in my box.

Thanks for the help guys I will try some of these

Yes, O-1 will air harden in thinner sections. You can spot anneal where you want to drill.