If you are having trouble with your Frankford Arsenal X-10 Press not fully indexing even after properly adjusting indexing per instruction and having to manually click the shell plate into detent OR your shell plate slams into detent too hard it's most likely that the issue is improper tension on the primer assembly release lever spring. 
 
Our tension adjuster simply bolts on with one bolt with no modifications and allows you to manually adjust the tension of the priming assembly to fine tune control of the shell plate.