I can�t seem to get concentric new brass. For instance, yesterday I started loading for a recently acquired .270. I start with 100 pieces of new Winchester brass of the same lot. I first ran them all through the sizer to straighten the dented and beaten mouths (this seems to do little to nothing in terms of helping concentricity). Then I trimmed all to the same length. Next I deburred the flash holes and uniformed the primer pockets. Then I chamfer both the inside and outside of the case mouths. I then cull all brass with weight variances greater than +- .75 % from the average weight (this results in a total weight variance of 1.5%). Finally, I check the neck wall thickness (with the appropriate Sinclair tool) and cull all with variances greater than .0015�. Out of 100 pieces I ended up with 74.

Now the problem. Over half have greater than .003� outside neck runout. After I load the bullet, the total runout averages .004� - .005�. Once the brass is fired, I can achieve probably .0025� total loaded bullet runout with the same dies (Redding FL sizer utilizing Redding competition shell holders, and a Forster competition seater with the micrometer adjustment).

Question is, is there anyway to size new brass to make it more concentric or do I have to load them all up and fire to have brass that is worth a shit. I guess it gives good practice

I would shoot them off, then never go near a full length sizer again. I neck size for 11 different calibers. Your brass (from neck sized/once fired brass) will be an exact match for your chamber which is really what you're seeking. You might want to get rid of your expander ball in the sizing die. It's notorious for pulling the cases out of round. Wilson neck sizing knock out dies will cure that problem real quick. It'll also let you put the press away. The press also has an efect on concentricity. You use only a rawhide mallet with the Wilsons. Best wishes.

Cal - Montreal

Geeez Buddy..all of that is way overkill unless you are shooting in some kind of world call competition with that 270 .

size them before you load them it will cut the runout to about .002.i had the same problem.like i said i had the same problem that took care of it,thanks,keith