Cheapest (may not be the best) route to try first is to make sure you have a nice chamfer on your brass neck opening. Size one case as you have been and measure the OD of it vs a loaded and see if you are pushing the bullet into a too tight neck. I have some cheap 300wsm dies that were really over sizing my brass and was hell trying to seat a bullet. As far as the seater goes, I use Forster if it's not a custom die and midway should have them for <$100 I think. The expander mandrel route we suggested is a better path than the rigid expanders most dies have.Anybody have any input on a decent setup that won't break the bank?