There was a list of 10 2-7/8 loads over on the Parker site. Should come up on a search over there or does using google. 1/31/ 2012 thread. Most is dated but some is current. Thread ran about ten pages. Your load should be fairly easy to come up with. Also Sherman Bell had several 10 loads he came up when testing barrels. Those got added to that thread.

The Ballistic products 10 bore Manuel is fairly poor to me. But all you need is one good load.