Anyone familiar with using Helicoils?

[white_2kgt]

It's a M10x1.25. I'm going to drill with the t-handle, and pray that it doesn't jack my threads up further.

If you drill it out you should remove ALL the threads. That is why you run the TAP down it to make NEW threads, then insert the coil to match up to your old bolt.

Don't use the drill bit in the T Handle, use the drill bit in a DRILL then use the t-handle for the TAP.