Expanding necks on new Lapua 6.5 creedmoor brass?

[p5200]

After reading about some of the Lapua brass have a lot of neck tension, would it be a good idea to run just the expansion ball in my Forster die down just far enough to get past the necks of the brass instead of using it as it comes new? I'm just getting ready to start load testing and thought maybe I should ask first. Thank you!

 

[Mauser06]

I always neck size and expand new brass...if nothing else just to make sure they are all round. Even Lapua cases get banged around in shipping. I always have 1 or 2 that are visibly out of round.

 

[p5200]

I don't have just a neck sizer but, can it be done the way I mentioned? I don't suppose I'd have to use any sizing lubricant just to do that?

 

[NZ_Fclass]

Why not full length size the new brass? If it is up to spec, no issues, if it isn't then you will have sorted the problem.

 

[p5200]

I've already primed 9 peices I guess I could FLS the rest. I think I'll just de-prime the 9 cases

 

[Kracken McGraw]

I've already primed 9 peices I guess I could FLS the rest. I think I'll just de-prime the 9 cases

Yes do as NZ_Fclass says. I just run shell holder up to top stroke and screw the Forster sizing down to just touching the shell holder, then full length size the brass.

 

[p5200]

Will do thanks!

 

[Straightshooter1]

I take my new Lapua or Peterson brass and run them through my Lee Collet Die to be sure the necks are round and it helps remove any edges on the rim that might be protruding towards the inside, which would otherwise make for some hard seating.

 

[mikecr]

What is the problem?
How would breaking Forster's expansion fix it?

 

[PhilC]

I've already primed 9 peices I guess I could FLS the rest. I think I'll just de-prime the 9 cases

No need to deprime, just remove the de-priming pin from the die, size those 9 cases, then reinstall pin.

 

[p5200]

No need to deprime, just remove the de-priming pin from the die, size those 9 cases, then reinstall pin.

I'd already de primed by the time I saw this I've done that before, don't know why I didn't think of it getting too old I guess lol!

 

[divingin]

Either way. I usually look at new brass a little skeptically until it's taken a trip through the rifle.

 

[8andbait]

You really should lube if full length sizing, even on new brass. I stuck a new one once and every time I looked at that box of 49 pieces it was a good reminder.

 

[XTR]

Typically I run all new brass over an expander mandrel. As for lube, I use imperial graphite.

 

[CA_Shooter]

I run an expander mandrel on new lapua 6.5 creedmoor brass. Nothing else, but that's just me

 

[D-4297]

My procedure for new cases ; regardless of "Brand" , is to deburr the neck , inside , and out . Lightly brush some Dri-lube in the neck , and run the correct size expander mandrel thru the neck . Prime , and load . That is pretty much all that's needed for Lapua cases to make them "First Fire" ready . Other brands , you may also want to check the flash hole for burrs . Not deburring the necks can cause case neck deformity , and damage both your die , and your expanders . If new cases don't "fit" into a chamber of a quality made rifle , then I suggest finding another "Brand" of cases . A Sling shooter I know gave me this procedure , as it is the process he uses for new cases , and it must work , because he has set World Records with new , out of the box , cases doing it this way . The majority of manufacturers make their cases to SAAMI specs , so that really shouldn't be a issue when talking about standard calibers , like .308 or .223 , or even .284 . My opinion is that Sizing new brass before shooting it for the first time doesn't do anything towards making it "FIT" your chamber .

 

[Ned Ludd]

In my hands, virgin Lapua brass can have a fairly wide range of neck tension (interference fit) straight out of the box. I size the necks down first with a FL bushing die and a bushing that would give approximately .003" neck tension. That is done so that all the necks are sized to some minimum I.D. that will allow the subsequent mandrel step to do some work and open them all up consistently. I then use the appropriate mandrel to open all the necks back up, typically a mandrel that is .0015" under bullet diameter, which will yield very close to .002" neck tension due to spring-back. Cases are then trimmed/chamfered using the Giraud trimmer. This last step often trims little, if any, it's mainly for the chamfer. Necks prepared this way seem to provide more uniform neck tension than un-prepped necks.

As D-4297 noted, this procedure is not about making the brass "fit" the chamber any better. As virgin brass, the cases should already chamber acceptably. The FL bushing die sizing step will not bump the shoulders if the die has been set up appropriately for the chamber, it only sizes the neck down, so a neck sizer die would probably work equally well. Brass prepped in this manner shoots very, very well and I have used it for matches on many occasions. I still prefer to use fire-formed brass for important matches, but the "prepped" virgin brass seems to be more consistent that when used straight out of the box.