What the... New Lapua 308 cases shrank .005+

[Turk10mm]

So I just got back from the range working up a load with new Lapua .308 brass. Berger 175 HVLD, Lapua Brass (minimal case prep), powder range from 43.6 - 44.8, Varget powder, CCI BR2 primer, Savage 10FCP suppressed.

All the brass oal was around 2.004-2.006 when new. Every case shrunk to about 1.997-1.999. I thought the brass was supposed to get longer not shorter?

 

[Temp9]

Re: What the... New Lapua 308 cases shrank .005+

Cases will get longer once you size them.

 

[High Binder]

Re: What the... New Lapua 308 cases shrank .005+

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Turk10mm</div><div class="ubbcode-body">

All the brass oal was around 2.004-2.006 when new. Every case shrunk to about 1.997-1.999. I thought the brass was supposed to get longer not shorter? </div></div>

The cases expanded in the chamber making them shorter.

 

[Turk10mm]

Re: What the... New Lapua 308 cases shrank .005+

Once I sized them they did get closer to their original length but most are still 2.004 with only a couple that actually grew.

thanks for the input, first time working with new brass.