Re: precison reloading questions
well, I'll give er a go...
1) you use your runout guage to see if your brass necks are centered perfectly with the rest of the case. It seems that new brass other than RWS lapua, norma has some runout prior to being fired the first time. I have found that my runout reduces significantly after I fire the brass and resize it the first time. I use the runout guage to tell me that my test loads have vertually no runout. That way I can always narrow my tests down to one adjustment (such as the amount of powder) at a time. If I am shooting a load that may have the perfect powder primer bullet combination but have runout, they may not group well and I will likely place the blame on the powder charge or whatever it was that I was trying to test on that particular test sequence. Use the guage to varify that your rounds are true. If they are not true, fire those and try again. If your die is giving you runout than it is probably because of the expander ball. I use a fine steel wool to polish the expander ball. it also helps to lube the inside of the case necks.
2) you use the comparator to know exactly where you are seating your bullets and to check to see if your bullet seating practices are producing consistent seating depths. The whole reason for a comparitor is that bullets measured from tip to base may vary a few thousanths, but the ogive to base should be much much closer. Supposedly, the comparitor will touch the ogive of the bullet...the same part that actually contacts the rifling first. I have noticed significant shifts in point of impact when the bullet seating depth varies a few thousandts. I have since been using the comparator a LOT. I also noticed that the amount of force I use in pushing on the press handle while seating bullets will shift the seating depth by a few thousands. I have since then just gently allowed the press to "bottom out" under minimal force. I used to just ram that handle down till it hit, hard usually.
play with your seating depth to check your bullet's "sweet" spot and record it so the next time you load that combination you can just use the comparator to set up to be IDENTICAL to the batch before.
3) I don't sort by neck thickness, not saying it doesn't pay, just that I don't do it. The only thing I can say is that if you turn your necks to a specific thickness that will make all necks the same. However, I think if you would use norma, lapua or even nosler brass you wouldn't need to turn necks ever. Also, if you are mix and matching winchester and remington and federal brass and trying to turn the necks to all match eachother, your wasting your time. Case volume from brand to brand is going to make much more difference than the neck tension IMHO.
4) If you turn your necks and you have zero runout your case neck is square with the rest of the case. BTW runout is in the case neck.
5). IMO the easiest way to set it up is to take a case that has been fired and gives you a slightly sticky bolt lift and measure it using a headspace guage. Then you take that case and start sizing. Start with the sizing die turned out 1 turn and size the case. Measure the case w/ the headspace guage again and if it is still the same length repeat the process turning the die in 1/8 of a turn. repeat until you have the case shrunk by .001 - .002" from what it was when you had a sticky bolt.
If you don't have a headspace guage you can do it by simply chambering your round and using the bolt "stickyness" as a guage. I have noticed that w/ my 300wsm, just prior to actually bumping the shoulder, the case shoulder will bulge forward slightly causing it to not be able to chamber. The sides of the case are being squeezed in a little causeing the shoulder to flex forward. just food for thought... my little experiences ;)
7)neck turning is a once per case job. Necks will not change.
I hope that this helps, Mark.
I used to re-load but now I "hand-load".
-- Well, at least I try
Last edited by britz; 02-21-2009 at 09:50 PM.
Reason: tried to make 1) clearer