New cases

[budget]

Hi guys, what do people generally do when they get new lapua cases. I use a mandrel to straighten out the necks on new lapua cases but are un happy with the scratches that are left on the inside of the cases. I have tried dipping them in moly powder but that doesn't seem so great.any ideas and what else could I try.
Thank you paul

[AlanF]

Paul,

Best way to straighten the necks is by loading and firing. Presumably they aren't so bad that they won't chamber? The processes I use with new Lapua 6.5x284 brass for a no turn 7mm Shehane are :

1. Ream primer pocket
2. Ream flash hole
3. Dip neck about 2mm into sizing wax surface and twist to get a little bit of wax on both inside and outside of neck
4. Expand neck to 7mm with expander mandrel
5. Neck size case with normal neck bushing
6. Wipe all wax off outside of case
7. Polish case mouth and outside of neck with steel wool
8. Nylon brush inside of neck (removes nearly all wax)
9. Load and fire with a light load of fast powder.

I find the necks will be almost straight after this, but after a second firing with normal load they'll be as good as they'll ever be.

[Tim L]

Alan,
How do you go with concentricity on a no turn?
Do case walls sort themselves out?

Running the 6.5 I find the outside of the neck is perfect after firing and less than a thou out after neck sizing (bushing), but the projectile concentricity ranges from 0 to 0.002" out.

[AlanF]

Alan,
How do you go with concentricity on a no turn?
Do case walls sort themselves out?

Running the 6.5 I find the outside of the neck is perfect after firing and less than a thou out after neck sizing (bushing), but the projectile concentricity ranges from 0 to 0.002" out.

If you're getting 0.002" max runout on the projectile Tim, then I can't help you any further because mine aren't that good!

[williada]

Budget, the thing you must do is jam your projectile into the lands for the first firing of a new case so that the wall of the case will expand equally. This will create a memory in the brass so future spring back will be more concentric. If new cases are not suspended centrally in the chamber, usually due to bullet free flight or short on headspace, they will most likely sit at six o'clock in the chamber, unless your chamber has a crush fit. When cases are sitting at six o'clock in the chamber, the upper wall of the case will thin and getting good concentric rounds will always be a problem.

After first firing you can neck size and just bump the shoulder .005". If you want superior results use a Lee collet die. If you want you can alter the neck tension on a Lee collet die by grinding the stem to a smaller diameter otherwise you need a custom full length die made to suit your chamber if you want to mean business.

Any remaining problems with concentricity will come from the alignment of dies in the press.

I thinks Tim's lack of run out comes from jamming his projectile all the time.

Regards, David.

[williada]

Paul, I for got to say in the previous post, that if you are getting scratches, your mandrel needs polishing, and it a good idea to lube the inside of the case with sizing lube on a cotton bud if you go down that path.

Another thing you can do is to polish the inside of the case neck. Use an old, stiff nylon brush and wrap some fine steel wool around it and slip the brush into a drill press. Turn the drill press on and then push with a sacrificial case push it up and down over the steel wool to size it. Then go about polishing your other cases. You may have to replace the steel wool regularly if you do a lot of cases.

I have made a purpose built brass mandrel with a slit in it to take steel wool rather than the old brush, which I wrap around with steel wool and place that in the drill press to polish the cases. Good luck, David.

[Seddo]

When i get a new box of Lapua i load them and shoot them, dont always size them either but i can be lazy and prefer to shoot each case before final load development.