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The precision mic.. The goal is to resize the case enough to fit and function safely, give good case life, and to achieve the best possible accuracy in that rifle.
With a lubed case in the shell holder, lower the press handle to raise the ram to the highest. Screw in the resizing die, with out the decapping rod and expander ball. Turn it until you feel resistance from the case. Now by turning the die 1/4 turn at a time and checking your progress with your head space gauge. You can adjust your resizing die to properly size your case for that rifle and only that rifle. (WARRING ; Never use ammunition made for one rifle in another rifle) When the die is set to the proper depth, insert a lubed case in the shell holder. Raise the ram to the highest point. This will keep the die from moving while you tighten the die's locking ring. Don't forget the rubber O-ring between the press and the locking ring. Once the locking ring is in place, insert the decapping rod, expander ball. The decapping pin needs to be low enough to nock out the spent primer, but you need the expander ball as close to the case neck as possible. With a lubed case in the shell holder and the ram at its highest point, tighten the decapping rod nut. Your are now ready to resize your cases. A word on case lubes, it doesn't matter which lube or method you use, what matters is getting consistent results. Check your consistency with your head space gauge. Be sure to clean off all lube from the cases after resizing.
Case trimming is the next step. Some people like to trim cases short, then shoot them until they grow to the SAAMI maximum length. I like to keep my cases as long (length- wise) as possible. I use a Sinclair Chamber length gauge to measure the length of my rifle chamber. By following the instructions, you can determine the exact case length for that rifle. There are two concerns when it comes to case length. First and most important is safety. The case can never be allow to become so long that it inters into the throat area of the rifle chamber. Dangerously high pressure will accrue. Second uniformity, all cases have to be the same length to achieve excellent accuracy. These are the reason why I trim cases every time I reload them. If you have a chamber length gauge, you can tailor your case length to fit your rifle exactly. If you don't have a chamber length gauge, just trim cases to standard SAAMI trim length, but trim them every time you reload them.
The process of trimming a case leaves a sharp edge on the case mouth. These sharp edges has to be removed, to prevent the scraping the side of the bullet when its seated in the case. Remove these edges with a chamfer/deburring tool. A few turns of the tool will remove all of the edges from the case mouth.
Primer pockets need our attention next, don't just scrape out the carbon. Primer pockets are not perfect. A primer pocket uniformer will cut all the primer pocket the same depth, and square up the inside shoulders. Uniformers are simple to use. Insert the uniformer into the primer pocket, with the case held against the cutter head and twist the tool until you feel no more resistance to the cutter. Be sure to clean the brass chips and carbon from the cutter head regularly to prevent build up. This allows you to achieve consistent primer pocket depths.
Now we go to the most neglected area of a case. Most factories manufacture a case, its punches the flash hole. This leaves tiny burrs around the edge of the flash hole inside the case. These burrs interfere with the primers ability to ignite the powder with any uniformity. A flash hole deburring tool will remove there burrs and creates a slight chamfer to the side of the flash hole. There are two types of flash hole deburring tools. One has a fixed cutter head, the other has a adjustable cutter head. Either one will do the job just fine, with a few twists of the handle. The best news is that you only have to do this once. Deburr your cases then put the tool away until you get more new cases.
The long process of case preparation is over. Before we go on, lets look back at what we have just done and why we did it. In a word "uniformity". Every step in case
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