Shoot them and reload for them , you will learn alot of do's and don't . Nothing beats experince. The 7 TCU is a nice cal. I shot one for several years . For cases I got 223 comerical ammo and fired it in the 7 TCU bbl. It would start the forming process . I did a thousand or more rounds this way. No its not accurate
. When I used a 7 TCU form die the cases split more.
If the bbl is loose the hinge pin can be changed and the bolts and springs can also. Only size your cases so the action closed tight with the bolts engaged about half way up or a bit more. You should not have to slam it shut. When I had a question I called TC they always helped out.