Poor tool life in O1

We got ours first and new VMC last week. One of the first job i had to do was milling a cam In O1. First ive never run this material before so i took a look at the endmill catalog to find some speed/feed. My boss end up giving me 250 sfm 0.002 IPT 0.250 Doc with a 1/2 3fl endmill (niagara S335 series). I had to do around 10 pocket 1.5 x 3.0 0.625 deep. on the 10th pocket the endmill begin to get louder and louder so i took a look at it after that and the bottom (0.250) of the endmill was kinda scrap. So i was wondering my boss told me to run this with coolant.

So should i slot with coolant in tool steel or any steel at all im use to slot in SS and we run coolant on almost everything in SS but is that the same in steel or we should run a little bit of air blast to remove chip and run dry ?

Also the control is a conversationnal control. The only toolpath i had to get in this pocket was to drill strait to the depth i need to rought the pocket or to ramp down (no helical entry). So i choose to ramp it with a 2.5 angle and half ste slotting feed. Is that too much or not enought because the endmill was doing a strange sound like it was rubbing or something like that. The kind of sound you dont like to hear from a new 65$ endmill.

Thanks helping me to become a bit better every week :)

Sébastien