Will try not to repeat what's already been said. This is a fairly simple process and concept so don't make it more complicated than necessary.
Comment of Sizing:
Full sizing also sizes the body of the case radially aiding in chamber fit. Since I'm primarily a hunter I strongly believe in full sizing every time. After many years of reloading using various methods, i.e. neck sizing, partial sizing, and full sizing I can attest that full sizing, done properly, does not reduce case life or degrade accuracy and produces reliable functioning reloads which is critical to a hunter.
Comments of Procedures:
While I use a bump gauge and caliper to set my FL die, the ultimate gauge is your rifle chamber. What you are trying to achieve is bolt closure with only very slight resistance of the case being chambered. The best way to gauge this is to remove the firing pin assembly so you can get a more exact feel of bolt resistance to chambering a sized case. Before gauges, the manual method was used quite successful to set up FL dies to obtain the optimum fit for that rifle chamber rather than just screwing the die down per the die mfg's instructions which often resulted in over sizing . I prefer to measure set back but the manual method still works.
The .001 to .002" shoulder set back measurement is the standard for bolt rifles. You simply measure the fired case with primer removed and set your FL die to push the shoulder back the desired amount. Check the sized case in your rifle chamber to verify that the case chambers with minimum resistance.
All this assumes you are using the same cases in the same rifle and rotating their use so that cases received uniform number of firings.
You don't need a lot of fancy equipment to measure set back. You just need a bump gauge and caliper. I like the Whidden gauges since they are caliber specific, inexpensive and simple to use with no inserts thus no interfaces. If you're reloading you should already have a suitable caliper.
As cases age or if you change brands you may have to adjust your FL die to obtain the desire set back. I like to check three cases every 2 reloads to make sure the die setting is still appropriate.
You don't special shell holders either which can be quite expensive.* They can be useful if you are loading for multiple rifles of the same caliber but even then you do need them. There are other effective and much cheaper methods for adjusting FL die for multiple rifles of the same caliper but I won't go into that here. If you are loading for a single rifle / caliber then all you need to do is adjust the FL die by tuning the die in small increments until you reach the set back you want.
*if you go this route make sure you check the dimensions. I had a friend who had two of them that were off about .002" from the marking inscribed on them.
Bottom Line: you want to size your cases to provide the optimum fit for your rifle chamber so that your reloads will chamber and extract flawlessly without over sizing the case.
Comment of Sizing:
Full sizing also sizes the body of the case radially aiding in chamber fit. Since I'm primarily a hunter I strongly believe in full sizing every time. After many years of reloading using various methods, i.e. neck sizing, partial sizing, and full sizing I can attest that full sizing, done properly, does not reduce case life or degrade accuracy and produces reliable functioning reloads which is critical to a hunter.
Comments of Procedures:
While I use a bump gauge and caliper to set my FL die, the ultimate gauge is your rifle chamber. What you are trying to achieve is bolt closure with only very slight resistance of the case being chambered. The best way to gauge this is to remove the firing pin assembly so you can get a more exact feel of bolt resistance to chambering a sized case. Before gauges, the manual method was used quite successful to set up FL dies to obtain the optimum fit for that rifle chamber rather than just screwing the die down per the die mfg's instructions which often resulted in over sizing . I prefer to measure set back but the manual method still works.
The .001 to .002" shoulder set back measurement is the standard for bolt rifles. You simply measure the fired case with primer removed and set your FL die to push the shoulder back the desired amount. Check the sized case in your rifle chamber to verify that the case chambers with minimum resistance.
All this assumes you are using the same cases in the same rifle and rotating their use so that cases received uniform number of firings.
You don't need a lot of fancy equipment to measure set back. You just need a bump gauge and caliper. I like the Whidden gauges since they are caliber specific, inexpensive and simple to use with no inserts thus no interfaces. If you're reloading you should already have a suitable caliper.
As cases age or if you change brands you may have to adjust your FL die to obtain the desire set back. I like to check three cases every 2 reloads to make sure the die setting is still appropriate.
You don't special shell holders either which can be quite expensive.* They can be useful if you are loading for multiple rifles of the same caliber but even then you do need them. There are other effective and much cheaper methods for adjusting FL die for multiple rifles of the same caliper but I won't go into that here. If you are loading for a single rifle / caliber then all you need to do is adjust the FL die by tuning the die in small increments until you reach the set back you want.
*if you go this route make sure you check the dimensions. I had a friend who had two of them that were off about .002" from the marking inscribed on them.
Bottom Line: you want to size your cases to provide the optimum fit for your rifle chamber so that your reloads will chamber and extract flawlessly without over sizing the case.
