venison_burger wrote:Is neck sizing virgin brass even necessary? Or am I missing something?
VB: Yes sir, you are. Virgin brass directly from the bag has necks that are dented, out of round, out of diameter tolerance (for proper neck tension), are usually not uniform in terms of length, and have manufacturing burrs inside and outside the mouth of the neck. The factory tumbles thousands of cases in large lots, all of them banging and crashing into one another, causing dents, goons, gouges, and other nasty things that would not qualify as a "precision operation". You don't want to start one of the most important steps in precison handloading with a case in that condition; that step being bullet seating.
Even though many don't trim virgin brass at the first loading because it will/does lengthen and sometimes even shrink a bit after the first firing, it is imperative that all virgin brass is sized. The caveat here is that full length sizing is really not necessary if the brass fits the chamber, as doing so will unnecessarily work brand new brass for no reason. Best to just neck size to uniform the case mouth and create proper bullet tension. You'll also want to chamfer the inside of the new case neck, and also deburr the outside of the neck prior to loading.
If you look at virgin brass straight out of the bag with your loupe or magnifyer, you'll be amazed at the extremely poor case neck/mouth condition of the brass, and will wonder how you even got bullets to seat properly in the past. Of course what you were actually doing was using the bullet as a mandrel to "size" the mouth of the case by press-fitting it into the case......not condusive to accuracy, and by shaving all that bullet jacket material off the slug with the burrs on the case mouth, that material went directly into copper vapor inside your barrel when you torched her off, lining your bore with copper fouling.
When I open a new bag of brass, I start out by neck sizing, then uniform the primer pocket, then deburr the flash hole. Using neck sized brass then ensures that the case mouth is perfectly round, and the flash hole deburring tool has a completely uniform surface to work from. Even if you don't uniform your brass (you should for peak accuracy), the neck sizing step is quite important prior to seating any bullets.
All the above assumes you're not weight-sorting the brass.....another topic altogether.
I don't need to FL size these cases do I?
Live and learn.
Don't feel like the Lone Ranger, Bitman!
