Do I Need to Prep New Brass?

[Crusader]

Hey guys,

Here's another brass prepping question, but different from the post right before mine, this is a basic one--is it necessary to prep new Lapua 6BR brass? If so, what do you do? I just got a box from Powder Valley and I want to make sure I do the right things as that stuff is expensive!

Thanks in advance.

 

[Preacher]

I like to run new brass through a expander die to even up all the neck tension before using them, new Lapua 6br brass as new seems to be a bit tight..
Some folks will just use a FL die...
Also a good idea to check that there are no burrs in the flash hole...

 

[Steve Wilson]

+1 on the expander die.

 

[Crusader]

I just have a full-length resizing die, so that would be alright?

So, no need to chamfer the new brass?

 

[Dave T]

+1 on the expander die. I recently prepped out a box of Lapua 6BR brass and found this brass to be very consistent, I just made sure there were no burs in flash hole without changing it's size and squared up primer pocket after first firing. JMHO
Dave T

 

[Shynloco]

I just have a full-length resizing die, so that would be alright?

So, no need to chamfer the new brass?

DO NOT DO IT! In the past I screwed up some new Lapua brass FL sizing it before fireforming it. As has been said, you only need to "expand" the necks using an Exapnder Die with new brass. If you don't have one, just load the brass and fireform it. THEN use your FL sizing Die to bump the shoulders if necessary. You might be able to get by with only an FL Die for hunting reloads, but no way for target or precision accuracy. And yes chamfer it so as to create that nice smooth entry into the neck when seating the bullet.

 

[Steve Blair]

My Lapua 6BR procedure is:
Expand necks
Trim to length for turning
Turn necks
Chamfer case mouth
Deburr flash hole with long #1 center drill
Load [br]
Obviously, if you have a standard chamber, you do not need to turn necks.

 

[Crusader]

Thanks for the replies. So, showing my ignorance here, who makes a good expander die and where's a good place to get one--Sinclair, Midway, etc?

 

[Steve Blair]

I use the Sinclair. There are others that probably work just as well.

 

[RonS]

Hey guys, I'm new to shooting a 6BR. Infact I'm in the process of my first 6BR build. I understand about using an expander to even out neck tension but why is it not good to use a FL die on virgin 6BR brass?

 

[spclark]

I just have a full-length resizing die, so that would be alright?

So, no need to chamfer the new brass?

You could use your FL die on new brass if you back the die off first so it's not doing anything to the case body. Leave the expander button in place though as you process brass, the idea being to make round any inconsistencies in case necks.

Likely as not new brass is sized to minimum chamber dimensions so shoulders particularly will be short (sometimes a lot!) of where your chamber's shoulder was cut.

You should also lightly chamfer inside & out too before loading. Brass gets dinged up in packaging & transport before it gets to you.

My routine includes annealing even new brass to make neck tension uniform; brass hardens with age & I have no idea how long a particular box has been on the shelf. Then I'll run necks over a K&M expander mandrel to make truly round, then chamfer necks, then use a K&M deburring tool on the flash hole. Once-fired then gets FL sized & necks turned to uniform thickness before reloading.

 

[Steve Blair]

Likely as not new brass is sized to minimum chamber dimensions so shoulders particularly will be short (sometimes a lot!) of where your chamber's shoulder was cut.

[br]
Another point is that I fire form with jammed bullets to minimize the problem described above. Some new cases are very short.