Home Forums Reloading Big Game Rifles Neck turn or sizing button problem

We'll I'm starting to seat bullets for load tests for a friends 300Wby. The cases are Wby factory brass from previous new wby ammo. Resized to be .001 of shoulder and trimmed to min length, beveled and deburred. I notice in the first few rounds the downstroke is a bit stiff to start and brass is coming off the bullet. The necks runout is all .0010-.0015. Bullet runout is .006-.008, which is unacceptable to me. I prefer ave of .002, but will accept up to .005.

Die's are simple RCBS standard dies. Would the problem be the diameter of the sizing button? The necks seem to have an inside diameter of .304 while the bullets are .3065, which I measured with standard calipers.

try lubing the inside of the case necks, works wonders to avoid the expander ball from yaning the neck out of alignment.

Size a couple without the expander button and measure. Then add the expander button and repeat. Could be the necks need to be turned/reamed. Not all brass is created perfect.

Neck runout is between .001 and .0015, so that isn't the problem. The bullet is out of alignment.

I have an RCBS gauge, should I try and measure neck thickness? How much smaller that the bullet diameter should the inside of the case mouth be? I measure about .0025 diff.

If you are peeling off brass from the bullet, you have a sharp edge. Are you peeling it off all the way around?
You say you have chamfered the inside lip of the neck of the case? Before you start grinding off stuff, you might want to take another turn or two with your chamfering tool on the inside edge of the neck and make a decided little "funnel" for the bullet to slip into. Just how carefully are you aligning the bullet when you bring the ram up to seat the bullet?

I will try chamfering some more, thought I have done a fairly meticulous job, like on my other reloads where I hae had no problems, plus I can feel more pressure than normal when seating the bullet. The brass is coming off all the way around. It's not a lot, but I'm trying to figure out why the bullet runout seems to be excessive.

You need to know what the diameter of your bullets are and what the ID of your cartridge neck is. You can get a rough idea by measuring a case w/o a bullet in it and then measuring a case with the bullet in it.

Sounds like brass spring back or undersized expander. Lube and a VLD expander may help.

Try different cases if you have them and see if you end up with the same dimensions. A new/larger expander could be ordered and polished to size. If it is brass spring back (memory) annealing could help. I am almost more in favor of annealing than neck turning, but both odious are tasks to be avoided for a hunting rifle if possible.