New lapua brass?

[mudduck]

Just got some new lapua brass for my 243 is there any prep I should do first or load it and shoot it?

 

[jonbearman]

Without knowing what type of chamber or gun you are shooting it out of it would be impossible to say exactly what to do. I personally run it all through a full length sizer to make sure the neck is round and free from defects.

 

[Keith Glasscock]

It depends on how they measure, and what level of accuracy you need.

For 1/2 MOA, I wouldn't bother with much more than rounding out the necks and chamfering the mouth.

For 3/8 MOA, I would measure necks and see if there is any need for turning.

For 1/4 MOA, I would check the flash holes for burrs.

For less than 1/4 MOA, I would suggest a light cleanup turn on the necks, flash hole reaming (Sinclair tools works well), and volume measurement after fire-forming. In addition, I would be on the lookout for odd ducks in the batch - even Lapua is not above having an outlier.

That's just how I operate my equipment, your mileage may vary...

 

[gotcha]

At minimum I would either F/L, neck or collet size for the reasons Jon stated and also to open the necks a bit to reduce bullet seating pressure. Factories are operating full tilt and I see evidence of brass being outside the parameters of normal Q.C. expectations. Including Lapua.

 

[Shynloco]

I'd check each piece for burrs, possibly chamfer the mouths and check for roundess, but otherwise, I fireform the brass before ever putting it into a die. I'm of the opinion there is nothing to be gained by taking new virgin brass and FL resizing it. All the serious an detailed prep work comes AFTER the fireforming process.

Alex

 

[savageshooter86]

Trim to a set length. Chamfer/deburr case mouth. Expand the necks and neck turn. Uniform primer pockets. Deburr flash holes.

This is what I do. "Match prep"

 

[Forum Boss]

Trim to a set length. Chamfer/deburr case mouth. Expand the necks and neck turn. Uniform primer pockets. Deburr flash holes.

This is what I do. "Match prep"

If you are using a no-turn chamber I would NOT do most of the above for a .243.

1. Visually check flash-holes to see if there are obstructions. Knock flakes out with a small bit as necessary.

2. Run an appropriate expander mandrel down the neck to ensure round-ness and release neck tension a little.

3. Very mild inside chamfer (don't try to remove much brass, just smooth the entry).

4. Trim to length after first firing -- that way you can keep the necks as long as possible.

Whether you FL size first or not, kind of depends on how the cases fit in your chamber.