As has been hinted at, follow the advice in the FAQs and the Handi basics, those steps will get you where you want to be. How you close the action and how you pull the trigger can cause a lot of grief, be consistent and close the action firmly, don't baby it, pull the trigger all the way to the rear each time. Number one on the list of things that can cause vertical stringing is poor/inconsistent lock up caused by oil on the latch and/or shelf, make sure they're dry. If that's been seen to, remove the forend and see how it shoots with it off, if it shoots good, work on it using the different techniques shown in the FAQs, one at a time, don't try a bunch of stuff at once.
I don't know how you arrived at those loads, but trying to pick a good load at random is a waste of powder, bullets and time, work the load up from start data in ½gr increments and you'll find the sweet spot.
Tim