Concentricity Issue - 338 LM

[Stuck]

Hi all,

I wonder if I can pick the collective brain please?

I've never been able to find a super accurate load for my Barnard 338 & have recently checked the concentricity of my rounds, to my horror I'm getting case neck run out of up to 0.020" on a loaded round. aaarggh

I initially put this down to cheap (Lee) dies so have upgraded to a Redding bushing set with a body bump die.

I've just measured the concentricity of 25 cases that have been through a Lee full length die (getting between 0.002" & 0.013") before putting them first through the Redding body die & then through the bushing neck size die.

When I measure them again their is a slight improvement but only by a couple of thousandths.

The brass is twice fired "Swiss Munitions" & I'm using my Rock Chucker press as the brass won't fit in my Coax.

Should I just accept that this brass is scrap or am I missing something?

[Christel]

[DaveT]

Hard to believe that the Redding dies could be that far at fault.

No idea about the brass quality.

I would suggest checking that your press and shell holder are squeaky clean and that the ram is free-running and then beg , steal or borrow a decent piece of brass , check it for concentricity and compare with post-sizing results on your gear.

I would suspect the press etc is skewed as my primary investrigation.

Also see if someone is prepared to take your original brass and see what results they get in their setup.

[Swamp Donkey]

I find that brass as much use for accuracy as chocolate is for fire guards. I know Lap brass isn't cheap, but it does the job well.