Crooked Ammo
Here are some procedures I have learned over the past 60 yrs that may be of some interest :
New bulk brass is usually lumpy around the shoulder and the case mouths are rough. Trim them slightly and champfer inside and out prior to running them thru your resizing die. The slightest burr can cause a bullet to seat crooked. Check the primer pocket for depth. You will probably find some that are too shallow and will result in a high primer. No use checking for concentricity yet due to lumpy shoulder.
Once fired brass should be inspected for defects and cleaned prior to sizing. Your dies will last a lot longer and you will make better ammo. Case necks should have all the carbon removed. The sooner you clean them the easier it is to remove. I use Cr 10 , Q tips, and a brass bore brush in a drill motor. Final wipe out with Q tip and brake cleaner or alcohol. If you are getting a little soot on the outside of case necks your load is little mild.
O K now we are about ready to use the dies. Start by making sure your dies are clean. Remove the decapping/ neck expanding assembly and set it aside. Check a once fired case for concentricity. It should be a mirror image of the inside of your chamber, little or no runout at the mouth. Put a little Imperial sizing lube on the case and run it thru the sizing die. Check the case for runout again . .003 runout at the mouth is within RCBS spec's.
Remove the expander ball and decapping pin from the decapping rod and check the rod for runout. Straighten as needed. Put the expander ball back on the rod , sans the decapping pin and check for runout on the ball. There is a slim chance it will be straight. If it isnt straight it can make the case necks crooked. Back the ball off a turn and see if it is straight. It will probably be pretty close. The problem is right where the threads end on the shaft. There is a slight taper from thread diameter to full diameter of the shaft. T here is enough slack in the threads to tip the ball cockeyed when you run it up on the taper. The fix is to put a little brass jamb nut on the shaft and run the ball up against the nut. Be sure the nut is smaller the the diameter of the ball. You will probably not be able to use the decapping pin with this arrangment but you will make straight ammo. Most of us use a universal decapping die anyway so the problem is moot
With clean brass and a smooth expander ball you wont need to inside lube the cases. Best of all you wont be pulling the necks crooked.
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