Problem on 243 Lapua brass expanded with Lee dies

[jpo]

Hi Guys,

I have 200 pieces of.243 Lapua brass that have necked up to .260.
I am using the Lee full length sizing 2 dies set.
,http://www.leeprecision.com/cgi/catalog/browse.cgi?1254564948.2305=/html/catalog/dies-rifle.html)
Before putting the brass thru the dies I checked them with Sinclair concentricity gauge to check run out.
It was .001 à .002' before necking up and between .004 and .007 after.
Has anybody got the same issue already?
Is that an issue?
What do you suggest?

Thanks for your help
jp

 

[fdshuster]

jp: I usually have runout after necking up or down, sometimes by as much as you experienced. The vast majority straightens out after the first firing, so I'm not concerned with it 'til after it's been fired. Also get some runout with unaltered new cases, although not as much. It too will straighten out after first firing. Some are reporting success by taking it in steps, .002' or .003' at a time, rather than one 'big one'.

 

[Rtheurer]

Great Reply by Frank.

You will have to fire form it once and then it will be NICE and Straight. If yo have issues after fireforming then there might be some concern. What your seeing is normal.

+ 1 with what Frank said.

RussT

 

[jpo]

Thanks a lot guys for your help.
jp

 

[KevinThomas]

I was about to dive in on this one, before I noticed that Frank has already covered this quite nicely. Thanks Frank!

Kevin Thomas
Lapua USA