Bullet Run Out

pdhunter

pdhunter

New member
Loading 22-250 using virgin W-W brass trimmed to 1.901. The test bullets are Hornady and Nosler 55 gr. BT and Speer 52 gr. HP's .
I am using RCBS competition dies.
I checked the run out on 15 of the loads with the virgin brass
with .006 to .009 variance.
When I checked the run out on some other loads using the same point but once fired win. brass. The run out was between
.003 and .005.
Any ideas whats going on ?
I have checked to make sure the case mouth is trimmed flat and the chamfering and deburring is even.
Thanks.
 
Are you resizing the virgin brass? I always size the brass---even virgin brass---before proceeding with the loading process. I've found that virgin brass is sometimes very inconsistent.

Also, on an unrelated note, when I seat the bullets, I seat part way, then raise the press arm & rotate the bullet 1/4 to 1/2 turn before finishing the seating. It seems to lower the runout a little more for me.
 
try leaving the expander/decapping rod a little loose when resizing. it centers itself when running the brass in the die. i had excessive runout on my 204 brass and tried this and it brought the runout down.
 
Another general tip that may help reduce runout:

The threads on reloading dies are generally coarse, with a lot of play. I read a tip where you set your dies as recommended by the manufacturer, but before setting the lock ring, remove the brass case and place a steel washer (with large hole) on the shell holder. Run the washer with shell holder up until it touches and removes all of the play out of the die, and then adjust the lock ring down till it stops and tighten it. This supposedly trues the die with the shell holder.

I use this both for resizing & seating dies.
 
Last edited:
I do resize my virgin brass just for the reason you stated
xminerat. I am going to try thsee thing and see what happens.
I checked the neck run out on some virgin w- w and some win.
The win brass has far less run out then the w-w brass. I belive neck thickness may come in to play here also.
 
I found my problem !
I thought my cases were being trimmed true to the base of the brass , but nope.
What I did was colored a 55 gr. point with a marker and seated the bullet - then pulled it . It was evedent that the neck was not flat. The problem lay in my trimmer.
So I , again , called RCBS and again they are sending me replacement parts for it.
 
pdhunter:

What do you mean when you say "...the neck was not flat"?

Are you saying the trimming on the case neck was not consistent i.e. not square?

And, when you state "...trimmed to the base of the brass" I take it you mean consistent length between the case HEAD and the [now trimmed] neck?
 
I have been using RCBS and Forster dies and I was getting alot of runout. I bought Lee delux dies and my run out is very minimal now. Any one else noticed a difference?
 
Buckeye- You nailed it . the word "square" eluded me the day I wrote that. Thanks for for clearing that up ( even to me )
Just another note - Yesterday I did a little experiment . I took a re sized case with trimmed squared necked and loaded
a point- the run out was .oo7 . Then I pulled the bullet and turned the neck and reloaded- the run out went to .004.
Just thought it was interesting.
I have never used lee deluxe dies but might give them a try.
 
Back
Top