I assume you are loading for a AR15 type action.
The first thing you really, really need is a cartridge headspace gage.
You need to set up your dies so you size to gage minimum for a gas gun.
You can also use the gage to determine just how much you are pushing the shoulder back on a fired case by measuring base depth before and after resizing.
You should not be crimping your round as crimping has collapsed shoulders and mucks up bullets.
Once we get you on the track of being able to measure just how much you are setting the shoulder back, and that the case is smaller than the chamber, the next step, assuming you are sizing correctly, is a small base die.