I was wondering if it would be legal for me to make my own high cap mags for my 10/22.

While no license, as such, is required for you to make large capacity feeding devices, the only legal reason to make them in the US is for LE/military/gov't export sales.  Any large capacity feeding devices you make would still have to be marked 'LEO only' in the manner required by 922(v).

Unless you were doing so as a business, then any magazines you made would be illegal for you to possess, after you made them.

If you wanted to manufacture magazines as a business, you could retain your stock for resale, and would have a right to do reasonable testing and quality control checks on your product - but I think you'd have to be actively doing business in LE mags (advertising, show some sales) to avoid jail if you somehow got on the ATF's radar.

Just my $.02.