Welcome aboard Jim! I've never handloaded for my 25-06 since it shoots 3 different factory loads so well out of the box with the first couple rounds touching or real close to it, these are all 115gr-120gr loads, so that's what I'd recommend for bullet choice, Nosler 115gr partition, Hornady 117gr BTSP and Rem 120gr Core-Lokts. Take a good look at the Handi Basics 101 sticky as well as the accurizing tips in the FAQs, you may already have a good load, just aren't shooting the Handi armed with the proper knowledge, it's not a matter of just pulling the trigger, there are some simple details that will make them shoot well, trigger pull, a clean and dry latch/shelf, closing the action properly, full length resizing and forend fit all make a big difference for starters.
Tim