Lapua brass

[dbaird]

Getting ready to load .223 using Lapua brass. Do I need to trim brass after sizing or wait until after the first firing? I have both the old brown box and the newer blue box brass-any preference?

 

[dedogs]

What's it for--bolt or gas-gun? Do you have the reamer print or know the exact length of the neck in your chamber? dedogs

 

[XBBR Shooter]

Getting ready to load .223 using Lapua brass. Do I need to trim brass after sizing or wait until after the first firing? I have both the old brown box and the newer blue box brass-any preference?

Shoot it first.

 

[NorCalMikie]

Get gauges from Sinclair to check chamber length. Check it and you'll probably see that the chamber is much longer than the Max trim length of the brass. Probably around .020" longer. Don't trim until actually needed.

 

[Fotheringill]

The first two boxes of 100 Lapua in .223 all measured between 1.745 and 1.755. I decided not to trim.

 

[LCazador]

If it's a custom chamber, you should know chamber length. Fireform, size, then trim and square up the case mouths. As you can see even Lapua brass can vary considerably. Trimming provides not only a consistent case length but a square case mouth!

 

[Ned Ludd]

For virgin brass (.223 or .308), I open the necks with a Sinclair oversized expander mandrel, then FL resize with the appropriate bushing to get better neck tension consistency. Afterwards, I trim, then chamfer/debur. Although I probably wouldn't do it for an important state, regional or national match, I have shot virgin brass prepared this way many times in local competitions and it has worked very well. In my hands on the first trimming, not much brass is typically removed, but the cases will be consistently the same length afterward. Does it matter that much until after the first firing? A lot will depend on the use and your precision requirements. For me, virgin brass shoots very well and the trimming step is simply part of the reloading regimen that I do the exact same way, every time.