.338 Edge Brass Prep Trouble--Poor Runout....

[300WinMagShooter]

I am new to the Edge caliber and am having some difficulties getting the virgin brass prepped well. I am using the .300 UM brass and Redding .338 UM dies to neck up. I frequently get very poor runout on the necks (sometimes up to 8 thousanths) when I check after using the FL die, so I have been resizing again with the neck die a time or two in order to get down to 2 thousanths or so. Using the same dies on fired brass does not give me any issues. Everything is well lubed and champfered with a VLD tool. Sometimes the neck runout is more than the bullet runout. My best accuracy is when the case neck has no more than .002" and the bullet has .002" or less.

My question is this: How much does neck runout affect accuracy if the bullet runout is acceptable? How is it that the bullet runout can be significantly less than the neck runout?

Thanks in advance for any help!
Jason

 

[Lightvarmint]

I am new to the Edge caliber and am having some difficulties getting the virgin brass prepped well. I am using the .300 UM brass and Redding .338 UM dies to neck up. I frequently get very poor runout on the necks (sometimes up to 8 thousanths) when I check after using the FL die, so I have been resizing again with the neck die a time or two in order to get down to 2 thousanths or so. Using the same dies on fired brass does not give me any issues. Everything is well lubed and champfered with a VLD tool. Sometimes the neck runout is more than the bullet runout. My best accuracy is when the case neck has no more than .002" and the bullet has .002" or less.

My question is this: How much does neck runout affect accuracy if the bullet runout is acceptable? How is it that the bullet runout can be significantly less than the neck runout?

Thanks in advance for any help!
Jason

I have seen this before on other cases.....

I think the source of the runout of your virgin brass is the expander ball in the 338 UM die. I only use the Sinclair expander mandrels to neck up and that makes the case forming operation very easy. Try it, you'll like it.

LV

 

[trueblue]

Excellent advice from Lightvarmint.
Sinclair expander body with their 338 expander mandrel is the best way to neck up to 338. Part #'s are:
Expander body- #NT-EXP
Expander mandrel - #E-33

The other option would be to use 375 RUM brass and neck down without the expander ball in the die body. Either way will give you less runout.

 

[300WinMagShooter]

Thanks for the input--I'll look into those options and see what I should do before getting a new batch of brass. Thanks again! Jason

 

[Shawn Carlock]

300WMS,

It helps on virgin brass with the redding dies to get the tapered expander button if you don't have it. Then on new brass run the case up only far enough to expand the neck but not up into the bushing. Once you have done that remove the expander button and run the brass full length in to the bushing only and this straightens the necks out really well. If you do not have a FL "S" bushing die I highly recommend getting one over the standard design. I get .002" or less runout on new brass easly. Oh it does make a big difference in accuracy going from .008-.009" down to .002-.000" runout.

 

[300WinMagShooter]

Thanks Shawn--I'm thinking that the sinclair equpiment that the other guys mentioned might be the ticket or I think I'll go for the S type and do as you said--the way its going now its too much work to end up with poor brass. On a side note, I know that a lot of guys are using an OAL of 3.785" (and mine seems to shoot best there as well) but I am curious to know how far off the lands that is for your rifles--mine hits the lands around 3.830". The reason I am wondering is that every one of my loads for every one of my Rem 700s have prefered the bullet right up to the lands, except for the Edge. Thanks for the input! Jason

 

[Shawn Carlock]

I have run 338 Edges with .000" to .050" jump and couldn't really get a constant variation, it just didn't seem to care.