Custom Sizing Die Question

[repiv]

For this Die I want to Full Length size with a custom die and I do NOT plan to use the expander ball. This is for a .308 but I am having trouble selecting the size I want.

If my math is correct I would want a .335 size but I am not sure.

Bullet .308 SMK 175
Case wall .029 (.0145 avg. on each side Lapua Brass)
Loaded round is .337

For a .0015-.002 neck tension I think I need a .335 to .3355 size die.

Does this sound right or am I missing something? Do I need to account for any spring back? I need some help with this one.

Thanks

 

[repiv]

Re: Custom Sizing Die Question

I ordered a .334 die to account for .001 spring back. Hope it works well. If not I will try a full size bushing die and adjust as needed.

If I am way off base here somebody please let me know.

 

[308sako]

Re: Custom Sizing Die Question

Yes, you are close, but you will eventually want an assortment of bushings to account for brass variations and wear. about .002 neck tension in clean and fresh brass works very well.