308 lapua brass new

[EasyGravy]

I just bought 300 lapua 308 brass new in box at a gun show for $150. I measured a bunch of cases and they are all right around 2.010. Now Im a little new to reloading so heres my question.

I have a lyman max case length guage and I know 308 max length is 2.015. Now I measure brass at 2.005-2.010 well under max length yet it doesnt fit in the lyman case length guage for 308.

I dont think the lyman case guage is acurate, measured the gap it says to be at 2.015 yet I measure it at 2.005.

Does anyone use a lyman case guage and notice the innacuracy?

Does anyone trim new lapua brass after the first sizing?

Any input would be appreciated, constructive critism always welcome, Im a marine I can take it..thanks brent

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[Cranedaddy]

That's a damn good deal.

I don't have a case gauge. Can't help you there.

I don't size my new brass until after the first firing and only if it needs it. The only prep I do to new brass is uniform the primer pockets and run the throat through the expander ball in my resizing die to get more uniform neck tension. New lapua brass is pretty tight. The batches of new lapua brass I got averaged .302 diameter and after I ran them through the expander ball they were .304 which matches my fired cases.

 

[Tempest 455]

The last two lots of Lapua I bought needed to be full re-sized and necks were VERY tight.

 

[DocB]

EG,

The trim-to length I've seen in most manuals is 2.002-5". This is a little short of the maximum length of 2.015", so that may be the difference. I won't get involved in the argument over the trim-to length vs. nominal SAMMI maximum.

HTH,
DocB

 

[EasyGravy]

I figured the was a few thousanths of personal preferance

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[SWThomas]

The gauge probably measures trim-to length, which is 2.005.

 

[gstaylorg]

I always trim new brass after the first resize, and every resize thereafter. Sometimes nothing is removed, but I do it for every case anyhow. As far as the Lyman gauge, can't help you there, but I'd not expect a quality set of calipers (Mitutoyo, etc) to be off by .010" (i.e.. won't fit the 2.015" gauge, but measures 2.005").

Also, virgin Lapua necks are generally pretty tight. Full-length re-sizing won't properly open up a neck that is too tight to start. If you're going to load up virgin cases, you probably want to look into an expander die/mandrel to open up the necks. You can full length re-size after the expander die if you wish, but it's not absolutely necessary and I rarely do that. With virgin brass opened up by the .308 [oversized] expander mandrel, I get ~ 1.0-1.5 thousandths neck tension for the first loading. Because the expander mandrel is supposed to be ~.001" less than the caliber, this fits pretty well with what I've measured. After the first firing, the necks are opened up sufficiently that the the bushing in the full length re-sizing die can do its job properly. The neck tension will generally be more consistent after the first firing/re-sizing because of this.

SINCLAIR GENERATION II EXPANDER DIES | Sinclair Intl

SINCLAIR EXPANDER MANDREL - OVERSIZED | Sinclair Intl

 

[ultrarunner7]

Mine ranged from 2.005 to 2.022. Full length resize, trim and fire form. Done

 

[29aholic]

Personally, neck size, load and shoot, then measure the cases and trim to the shortest length in the lot to keep them consistent.

 

[EasyGravy]

I full length sized and they were all aroun 2.010 so I shotem

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[29aholic]

good shooting

 

[the m700 project]

Check out the stickies in the reloading forum theres a good write up on how to prep for accuracy. It says trimming back to minimum might not be what is best. Perhaps put it in a case gauge and see what you got if everything seems ok reload it to factory spec for fireforming.