I cannot even imagine what kind of cheap caliper you may have that has only a resolution of .01". The $20 Harbor Frieght models go to .0005 (inch) resolution, but read in .01 mm resolution. It sounds as though you are reading inches, but...
There are plenty of odds and ends you really should have in this 'hobby'; the aforementioned check-weights and a bullet puller are but 2 of them. You can actually get collet style pullers that will work in your press.
Since you are using a SS press, you should have plenty of time and opportunity to examine your work prior to making 100 similar mistakes.