BP 2 HP Var "Crash" - Things to look for?

I was trying to cut a 3" circle in .125 hardened steel - it was from a scrap bin so I'm not sure exactly how hard but a .22 long rifle round left only a smudge of lead. I was using a boring head and a cutter of my own devising at the end of a boring bar. I was taking it slow and it seemed to be working, though the mill/set-up didn't sound happy, when the cutter bound up. The vise, a 6" Kurt on a swivel base, was bolted to the table (though it must have loosened), shifted to the right and the cutter skipped out of the cut and dug in hard and stopped turning. I had my hand on the switch and cut it off almost immediately. The mill head was canted about 10-15 degrees to the left. I loosened the 4 bolts on the front of the head and used the adjusting bolt on the right side to bring it back to vertical and trammed it back in. The gearing on the adjusting bolt seemed to be solid in both directions. I looked for cracks in the housing and ran everything and it all seems OK but I have a nagging doubt that I'm missing something (other than training). Is there something I should be looking for? Did I dodge a bullet by just snugging down the 4 bolts on the front the last time I trammed in the head and it's a good thing that it slipped?

On advice on cutting circles in hardened steel, I'm all ears, but Tuesday I'm getting a plasma cutter.

Thanks in advance for any advice.

Use a hole saw and clean up with the boring head.

I have seen the bolts dig into the circular t slot behind the head. Raise the knee dont use the quill or the power down feed to do something like this. Better to use a hole saw and go slow in back gear.

Thanks guys - I will get hole saws. KP, I was at the bottom of the low range and raising the knee/table into the cutter - it was just a poorly conceived and executed attempt to make do with what I had on hand. I've checked everything out that I know to check and it all seems to be working fine - quill moves smoothly and easily, down-feed is fine, brake, quill lock, etc. If I understood your comment on the bolts digging in, wouldn't I have to remove the entire head assembly to see that? I did use the head tilt adjusting bolt to tilt the head in both directions and didn't feel any odd catching or hear any metal complaining. Maybe I was just lucky. I did order SteveWB's "A Guide to Renovating . . . " a 2J this morning just in case - as well as the one for my South Bend Heavy 10 - support living authors!

Thanks again and happy new year.