Virgin brass

Any other brand, I would say size them. Lapua, you should be fine just running the mandrel through them, for the obvious reason that some are dented.

Mandrel rounds out the necks and sets tension. I use the turning mandrel which is .001 smaller than the expander.

Lapua and Nosler are the two that are nearly perfect out of the box. All other brands should be treated as once fired.

I have loaded new Lapua, Nosler, Remington and other brands of new brass and have NEVER sized or trimmed any of it with one exception. The only new brass I size is 460 S&W Magnum brass to be shot in a revolver; if I don't size it and have a good crimp, the bullets walk under recoil.

Resizing new brass will probably worsen accuracy rather than improve it.

MWC1974 said:

Lapua and Nosler are the two that are nearly perfect out of the box. All other brands should be treated as once fired.

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Yup. I even run *-* (Starline) brass through a sizing die before loading the first time. I get maybe two out of thirty that are oversize or oblong out of every batch. Starline, in my experience (YMMV) has been the most consistent commercial mass-market brass around. Rem used to be real good, Federal ditto, Winchester is hit-n-miss but mostly good from the box, fresh.

I always run new brass through the sizer and chamfer the mouth, including Lapua. I'm generally shooting for optimum accuracy so having everything as uniform as I can make it supports this goal.

Vloc1987 said:

so I have the Redding 3 die set, neck sizer, full length/ shoulder bump sizer and the seating die. Would it be good just to neck size it only without using the body die on it?

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I run new and fired brass through my FL die. I don’t neck size. New brass will have the shoulder in a position to fit all chambers. Your FL die will not come in contact with it. What you’re doing is uniforming the neck of your new brass to get consistent neck tension.

After you fire your new brass for the first time the case will form to your chamber’s dimensions and then you’ll need to bump the shoulder back 0.002”-0.003”

Neck sizing vs FL sizing is another subject that will generate strong opinions on both sides. Suffice to say that when it comes to accuracy, every modern competitive shooter who strives for the most accurate load they can make will FL sizes their brass.

All new brass is sized and trimmed- just the way I work.

I've been sizing all my new brass. I read here it was a good thing to do. All Starline btw.

Add me to the list that treats any “new to me” brass the same regardless if it’s been previously fired or not.

I know the stuff that runs through MY dies work for the rifles they are set for.

Vloc1987 said:

So would it be best to get a factory crimp die for the first firing. I assume after I resize fired brass and use my bushing dies then I will have enough neck tension to not use a factory crimp die?

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I have a 308 Winchester for which I use Lapua brass and have found no need to crimp it at all. You shouldn't have to crimp for the first or later firings. The 460 S&W Magnum is a special case; i.e., a lot of recoil in a handgun.

There are some cartridges I do crimp; things like the 375 H&H Magnum and larger. I don't crimp 300 Weatherby Magnum cartridges and have never had a problem. For cartridges that I crimp, I prefer Lee Factory Crimp dies but use roll crimp dies for some straight wall cartridges.

I've never used virgin Lapua brass but the last Hornaday I bought I found a little over 10% was longer than the rest, Starline was just a little better, I like all my brass to be consistent especially when trying for accuracy (annealed, weight and length).